I've had a very similar case study like this one. 2003 escape. Ultimately came down to finding that the instrument cluster had a bad diode, leaking voltage into the ignition power circuit that backfed the control side of a relay keeping that relay latched, providing power to the vehicle keeping the vehicle running. my move is exactly what you're doing in the bonus footage. These ones are always a challenge lol. (I actually ripped apart that instrument cluster and replaced the smc diode on the board and got the customer their car back vs throwing in a reman or used. pretty sweet)
@@deniscarr469 Very, very good point. If my memory isn't crap, 2-3 hours to narrow it down to the cluster. Then about 30min-1hr testing on the board and fixing it. Luckily the diode had a witness mark so it was easy to tell where the magic pixies went 🤣 add another two hours for a trip to fry's electronics (may they rest in peace) and reassembly. Definitely didn't charge them enough to cover a whole day project. Think I did diag, an hour for r+r, and $100 for the cluster fix. Eh, you win some, you lose some. Lady still comes back to see me every time she's got a problem though. Hard to come by in a woman, loyalty. 🤣
Hello Iven, i smiled and clicked your video as soon as i saw the thumbnail! A new BCM will fix this car, i've been through a 2018 elite with the exact same symptoms and that was the fix. I am actually surprised it only took you an hour to reach that conclusion hence it took me a full day to make the call 😅. You are an excellent tech, and i am glade you decided to share your knowledge with the community. Good luck
Hey Ivan. I ran into this same problem with a 2017 crv a year ago. The BCM was unavailable.(still isn't) That really sucks for the customer. I even opened up the module to inspect for a possible manufacturing error. Found nothing. I do automotive electrical and diagnostic work for a living, and your right, the newer these cars get, the harder it is to find modules should they go bad. Good luck with your odyssey. My temporary solution was a constant duty solenoid to power up the micu/BCM.
This is not an isolated instance, other Honda owners of similar age models (e.g. Civic, Pilot, CRV) have experienced the same symptoms and have either had the BCM replaced or are waiting for them to become available. There are a few people saying the keyless entry module was the cause, this is much cheaper and available so may be worth a look.
As a Honda Technician, if we have a vehicle that powers itself on by itself (usually also comes with intermittent alarm), and we see the gauge cluster turned on with the key nowhere near the vehicle, we know it's a BCM issue. Also for IGN1 alarms where the car sets off its alarm randomly by itself. On some models its the keyless entry instead of the BCM, but I believe that's really only on the Pilots. Basically whichever module controls 'turning on' the car when the start button is pressed, is the culprit.
I had something like this on a 1981 Ford Thunderbird Heritage Edition. This car had the electronic dashboard and things I had never seen in a car before. The interior lights and the dashboard were coming on by themselves. Now, this is long before any modern electronics or canbus or anything. I had a repair manual that was for the electrical and it contained flow charts. I messed with that thing for 2 days. It would be sitting outside and the interior lights would come on and the dashboard would light up. Turned out to be a bad lighting control module that was backfeeding through the ignition. This video reminds me of that. Great video!
Ive seen this befor on my friends 2015 Colorado, he didn't fix it and problem got worse , eventually got to the point of engine starting and running by itself.. He had a rear leaking window that sometimes caused alot of moisture inside and I figured that may have somehow ruined the bcm. Replaced BCM and he hasn't had any problems since. So i believe you made the right call PH.
Miss the good old days when you could climb into the engine compartment to do repairs, actually see the spark plugs before you remove them, change a headlight for 5 bucks and a tail light for 50 cents, 7 dollars for a wheel bearing instead of 250 for a hub assembly.
The good old days when head lights had the brightness of a firefly in a mason jar, a 5.7l v8 made 120hp, a mid size family car got 14 mpg, and if you hit anything you were instantly killed.
This seems very similar to an issue my dad had with his 2018 Ridgeline. Honda has a service bulletin to replace the keyless access control unit. The alarm would also go off for no reason at times. Parts were not available for the ridgeline, the dealership turned off the smart lock feature and the issue has not returned.
I own a 2018 Odyssey with almost identical symptoms including the weird “lost power to alarm..” message on screen. It is very intermittent but the car has left me at least 5 times with a dead battery. I’m in SoCal and car has
Must be infuriating. Just out of warranty.....or is it? Is there dust in or on the connections? Maybe a lot of thieves are just driving around trying codes or seeing whose lights come on. Maybe drive in a different area.......
2019 Honda Odyssey elite 90K milesl, so initially, the Lane detection camera ($700 part) has been bad, but I have been driving it anyway for months buying time. However, now the car will not shut off? I think it is unrelated to the many lane camera error messages. I had to pull the battery cable off to stop the engine; then it that reset computer (?)and it started it fine, seemed ok. Locked it up and went to bed only to wake up to the horn alarm going off later! The key remote didn't work to turn off the alarm!. So I had to use the 'real key' inside the fob to open the door the old fashion way. I found out if I don't lock it the security system won't go off like that. However, the accessory power still comes on by itself!! I caught it twice but now my battery is dead or drained from the accessory going on. I see other's pointing to the ignition switch as the cause. I will update.
This reminds me of a similar case I had with a 2015 BMW F20 1 series. The fuel pump would start running full speed at random when the car was parked and should be asleep. Eventually causing the battery to be discharged over night. The fuel pump is controlled by a fuel pump control modules that regulates the fuel pump speed based on fuel demand coming from the engine control unit. A BMW dealership already replaced the fuel pump control module to no avail. When it came to me I knew that the fuel pump should only be running at 100% if the fuel pump module is awake but has no communication with the engine control unit. Looking at a diagram it has a wakeup line. When it was acting up the wakeup line was raised to 12v thus waking up the module even though the engine control unit wasn't requesting fuel flow, causing it to start running at full speed. Looking at the diagram I disconnected every module on that wakeup line one by one and determined the FEM (Front Electronics Module, basically like a BCM controls everything like ignition, lighting, power windows, door locks, starter relay etc. ) was outputting 12v on the wakeup line when it shouldn't. I was ready to call the FEM until I found not a single used unit with Comfort Access like the car had and a new one from the dealer was way out of the customers budget. With that in mind I decided to dig a little deeper. When it acted up again I started removing connectors from the FEM one by one and noticed when I pulled 3 specific connectors out of the 10 that were connected to the FEM the fuel pump turned back off. Looking at pinouts for those connectors nothing looked really interesting except for a wakeup line going exclusively to the instrument cluster. I had noticed that when the car acted up the indicator lights on the cluster would light up. And what do you know, when pulling the pin for the cluster wakeup line out of the connector and reinserting the connector into the FEM the fuel pump remained silent. I reinserted that pin and just disconnected the the connector at the back of the cluster. Left the car for 2 days and 2 nights. Battery wasn't drained while it would be dead every morning cause of the fuel pump issue. Got a used instrument cluster, virginised it, programmed it to the car and the problem was solved. Sometimes you've just gotta know how the system works and dig a little deeper even though the answer looks straight forward. It might not be.
Your event gives credence to fears of artifical intelligence going amok. It is always an 'adventure' when you share your troubleshooting. And you always seem to encounter the most perplexing of problems.
Hi Ivan.You're making the right call in the circumstances. Financially it's a no brainer - change BCM. From the customer's point of view he/she could end up paying for hours and hours of diagnostic time for no result.
Ivan good call.(maybe) In the early 1980s Volvo had a similar problem with the Volvo 340 CVT model. If you left the car and closed the drivers door sometimes the car would start and if you left it in gear the car would start up and drive away !!!!. They introduced and new fuse box( now called BCM) and a different gear lever with a buzzer fitted to try a warn people to not leave it in gear.
Hi Ivan, I've been working in the field for 15 years and for the last year I've been watching all your videos, I've learned a lot and I apply it in my work too, you help me a lot, thank you. Your videos are great and I always watch them with an interesting, healthy and very happy look. Greetings from Israel :)
All the symptoms are pointing to a problem at the BCM. Either a faulty connection to, or a faulty module itself. It is really difficult to tell at this point, but I can't argue with your hypothesis either as it does seem that the BCM is the most probable suspect. Something that caught my attention though was, there is an "updated" part listing for the BCM on a 5-year-old vehicle. Not an identical replacement part. And no related TSB's on it. Just something that makes you go humm? I am looking forward to part 2.
Odysseys, Pilots, Ridgeline, CRV and Civic all could have this issue. Correct with BCM diagnosis. Check alarm history and see if "ignition switch" was a alarm trigger. It's usually a good indication of BCM ghosting ignition to run position. I have waited over 8+ months to get BCM from Honda. Try and source a used unit. Be sure parts numbers are correct. They have different part numbers for different trim lines in the same year. As far as I know they are not flashable to different trim lines. Good content Ivan. Thanks,
Hey. Great video...my 2013 Honda Pilot 55,000 mi also was possessed. Navigation and radio constantly rebooted, headlights flash, close object warning flashes. All without the key present...and it would not start ...$2300 later it was a bad micu and 2 shorts in the wiring harness. omg
BCM Is the correct educated guess, I'm seeing this issue more often lately. Only dealer tool will be able to program the new BCM/Used. There is no flashing for the New or used BCM only immo needs to be learnt, Original keys can be reused. Used Bcm with same part number can also be used.
I've seen this once. The owner put a spare key in a magnetic hide- a- key under the car. After market ebay key of course...... It would get wet and yup! Took weeks to pry that info out of customer.
My 2014 Ford F-150 has the ECU (electric control unit) turns lights and ignition on and drains the battery overnight. I have had it to the dealer under warranty numerous times and they can't find anything wrong. It is a fairly common problem with Fords but the dealers won't acknowledge it. You are correct in your assessment of "stupid smart cars" I work on classic cars, points, plugs and condensers. And I can fix things not just throw parts at a car like the dealer techs do.
We fixed a couple pilots doing that At the dealership those two pilots would also sound the alarm of course conveniently at 1 o’clock in the morning lol
@@PineHollowAutoDiagnostics 17 Pilot Elite Smart power control unit module and I miss spoke earlier it was a 17 or 18 Ridgeline. Smart power control unit. I didn’t look at our interactive network site I’m not sure if odyssey even uses this module but it certainly affects pilots I believe even a civic it would just turn the key on and sometimes you could not even turn it off with the button but I could be off Mark on this one I’m not sure if that Odyssey uses the smart module or not On the pilot it’s on the passenger side flip down the glove box mounted with one bolt below the airbag.
Intermittents are such fun! I've had them before, some take many days to locate. The wiring diagram was the main helper along with one DMM and one Fluke 98 scope in DMM mode. No green crusties, but a lot of heat related problems that caused the Intermittents. A heat gun sometimes helped. You'll find it.
With a computer involved, anything can happen. All it takes is a tiny leakage current to common in a capacitor tied to a processor input normally pulled high, or a switch mode power supply or power converter with too much AC ripple. Somewhere, there is a logic 0 or logic 1 that turns on the ignition, and whether that tiny signal should be high or low, it doesn't take much to change it. I think you get these cases because of your superior intellect and logical thinking.
Part of me would wonder if there is a key hiding somewhere. I’d delete out any keys but what you have, Just in case. There should be an encryption code shared between the ecm/bcm for each key that should be needed to power up the car. Replacing the BCM should invalidate the keys, and would also cause the same outcome. It will be interesting if you can pair the bcm/ecm or if a dealer will have to do it.
I had found a set of fobs with factory build sheet while detailing my Chevy truck. They were between upper back seat and cab wall. I saw a little piece of plastic hanging down and didn't know what it was until I kept pulling at it to get it out.
I feel your pain on Honda parts availability. My sister-in-laws 2018 Fit was rear ended in late December 2021. Took until August 2022 to get all the parts to repair it!
You know Ivan, putting a kill switch wired to the BCM would be a cheaper solution to the problem AND I think also a great theft deterrent. If a crook steals the FOB RF signal, there will be no way in hell they could steal the vehicle. I know push button start and theft is a huge problem for Toyota but all push button start cars are susceptible.
Keyless access module. We’ve seen a lot of them on the Acura side. If the alarm was set, the alarm would go off and store a “IG1” as the trigger device.
You mentioned adding a switch. How about turning off the Batt supply to the BCM? Maybe try that as a test first? Hoping to see a solution in part 2. Thanks for this part.
I haven't read all the comments so don't know if this was asked/answered. Thinktool is powerful .. maybe try re-initializing the BCM right up front, before anything else?
Ivan, you have us as perplexed as you must be feeling right now. Just changed the oil in my 97 Dodge Truck and 02 Caravan. Can't say I'm really ready for what the automotive future looks like right now. Hope to get a some more time on the vehicles I have now. Trick or Treat? Thanks for Sharing!
Guided parts cannon.... Not just the parts cannon. Big difference! But agreed, what else could it be what actually controls the keyless and starts that car?
YOUR ON THE RIGHT TRACK HAVE MANY WITH THIS ISSUE, ALWAYS A DIFFERENT ISSUE, INTERMITTENT, OR STAYS ON ALL THE TIME AND KILLS THE BATTERY. OUR ALARM GOES OFF. THE BCM HARD TI GETS TO ABOVE THE FUSE BOX, WHICH HAPPENS ACROSS ALL HONDAS NP TSB FOR THIS
I had a crv a while back that was a parasitic draw. This new town i moved into has a big problem with draws. I went 6 years as a tech in my hometown and only ever had 1 parasitic draw that was something real easy that i have forgotten what it was. Here I've had like 5-6 cars with draws in the year i have lived here. Anyways this crv at first I found the radio was staying on. My draw went away when I unplugged it so I replaced the radio. Supposedly that wasn't the fix when the customer returned about 3 months later saying he was still having a dead battery. It then took a few visits to the shop because he would need the vehicle to get to work and couldn't leave it for any reasonable length of time but I finally found that the MICU/BCM was actually the issue and was keeping the Radio on at all times. I dug deeper when I found that new radio was staying on again. Lesson learned. Anyways all that to say that the BCM for that car took 5 months to get and same thing I think it was a 2015-2018. Somewhere around there
Apparently Honda has the biggest problem with parts...buy an alternator while you can get it - you'll need it. Great work Ivan and looking forward to part B:)
I agree with your diagnosis but one problem I see is that let say the bcm is (seeing the key ) and turning the ignition on. I would think the car would start when pressing on the brake and pushing the start button when the ignition is on. Also I noticed what appears to be the red security light flashing on the cluster when the ignition comes on. I’m not disagreeing with you but It would be hard to call it the bcm when the fuse box could cause this too. Only way to tell is to isolate the ignition control feeds from the bcm to the fuse box. I enjoy your videos
I had a 2019 Honda passport, all kinds of electrical issues. I had same issue as well as the vehicle would brake on its own, accelerate on its own. Rear tailgate opened with no command. Radio was an issue with noise, the dealer would do noting for me. I had less than fifteen thousand kilometers on it. Never solved it and got rid of it.
Nearly a year ago our Ford had a problem. Towed to a dealer and waited a month for parts. Corporate said they don't have an ETA for parts and, at the time, the dealer said he had about 10 cars waiting for parts. Had to purchase a new car. Fortunately, a dealer gave us book price for our non-running, but warrantied car. Are we still blaming covid for this? Great video. Thanks
Try resetting the bcm by disconecting both positive and negative on battery and take 1jumper cable and connect positive and negative leads to engine together for 20mins and do these steps in reverse and bcm should go back to factory default settings, therefore fixing your problem. U r welcome.
What was so difficult about putting a key in a hole and turning it to start? The systems with a chip in a proper key were probably the most secure and reliable in my opinion.
Go ahead and change the bcm, and trust your work, and yes cars are becoming disposable items!, I hate this start stop gizmos. Looking forward to the next vid
just started watching... perhaps one idea would be to do a full scan without turning the ignition on when the car acts up. just to se what if any modules is responding... to se what modules got power and narrow it down that way.
I would try to scope between BCM, ignition key on. See what's happening, what kind of voltage drop is going on there. Other idea is to look at salvage yard, take kne from there if you can find 2016-2018 Honda Odyssey Elite What if the bcm is faulty triggering the key on but the relay switch is stuck on continuously giving ground making it so only one faulty signal is needed to make bcm think key is in proximity.
Does the car have "On-Star" type capability that can remotely start the car (without the key being needed)? Maybe that system has gone haywire. Also, I noticed a big dent on the driver side front fender. Maybe the car was in an accident and some wires got got messed with? Looking forward to Part 2, Ivan!!!
What device actually reads the presence of the key inside the vehicle? Is that device directly connected to the ignition button? My thought is if those two items are part of the same module behind the dash, then the BCM could be ok and that button-and-antenna module could be telling stories to the BCM. On the other hand, if they're completely separate, then it's more likely to be a fault in the BCM itself. Guess we'll see in part deux.
BCM is a well educated guess, maybe keyless entry module, did not look like it had any aftermarket remote start installed. Now you just have to find one, possibly reprogram a used one ?
I am curious as to why the dealer blamed the liftgate control module. That is a module that should have power at all times. Could it be feeding power back into the BCM? Seem like it would be a simple test to disconnect the liftgate control module when the car is acting up and see if the power to the cluster goes away.
Bcm/keyless access module common on these Hondas and Acuras to cause this same problem as well as other problems. Keyless access module is part of the bcm on this Odyssey. Alldata has good info on the system description of the keyless access system, there is no literature of your issue, but it’s common and yes the bcm has been on back order for a long time
Unfortunately, my wife's 2017 Honda CRV is doing exactly the same thing. I watched both part 1 and part 2 of your diagnostics on the van. How is it possible that a vehicle with a proximity key starts itself without the key being present? Exactly what her CRV is doing. It only has 33k on it. Sadly, it's out of warranty because it's a 2017. I have no idea how much money this is going to cost to get it back up and running. Thanks for the video. Much appreciated 🙏
I would disable the keyless entry and remote start. You had a issue with door locks and power doors. Dealer had reason to fault rear hatch that may also be keyless entry fault.
Hey Ivan, if needed I could send you an install guide for the add on remote start units that are basically plug and play. I have seen this same problem with a push to start Accord that turned out to be a faulty remote start. Also try pressing lock on the factory remote 3 times. If it has an add on remote start this should activate it.
I think replacing the BCM is a good call. We had a similar problem on one of our 2016 F-150's. At random the DRL lights would come on and there was about a 20 amp draw when it was acting up with nobody inside key out and doors locked. I messed around with it and we ended up taking it to the dealer. They had it for about two months and the mechanic traced it down to no bulbs in the cargo light. The upfitters removed the bulbs when they installed the cap and he said the BCM was searching for those bulbs, couldn't find them and was acting up. There was a code for the puddle lamps. It fixed the problem when he pet the bulbs back in
Ivan, I still drive a 95 Honda passport/ Isuzu rodeo. 325k on original motor and transmission. I changed the plugs recently and decided to check compression. 170 psi on all cylinders. Last emissions test HC was 21 and CO 0.01. I've beat the piss out of it in the mountains hear in Boise. I just maintain it really well. Got lifter noise, but what 3.2 dosent. Lol
The sliding door not opening might not be "stupid smart cars", but a very good clue. I'd troubleshoot that, as it might lead you to the main suspect; the BCM😊
We had a BMW that would just spontaneously lower all the windows. It especially happened within 5 minutes of parking the car. Sometimes I would turn the car off in a parking lot, get tied up on something before walking away too far, suddenly hear a whir, "What was that?" Go back to the car and all the windows were down. Other times I would return from the store only to find all the windows down. And it was raining.
I had a VW Jetta as a loaner that actually had a warning in the manual that the door handle touch pad could actually trigger the "feature" to lower all the windows if you hit it with a car wash spray in just the right pattern. You'd think they would have clued in that this indicated that "feature" wasn't thought out very well..
Bad BCM, had that on 2020 civic Upd on the tap on bcm - if you crack bcm open youll find overheating signs on the main mcu, i believe its RH850 from renesas, if not mistaken
Seen so many of these on Acuras, used to work at the dealer. Ends up being the Keyless Access Unit (some have TPMS built in) or BCM on the newer cars. I'm not sure if you can check with other scan tools but if you check with the HDS, in the Body Electrical > Security history. It will have an alarm trigger by the Ignition Switch.
when that Honda is parked there is a gas tank purge valve that depressors the gas tank some times they stay on , it works to depressor the gas tank even when the engine is off lol
You have a thing for weird cases, Ivan :-) It seems like a very educated guess to get a new BCM! IMHO, a leaking capacitor can bridge tracks of a PCB and pass low current intermittent signals where they shouldn't go (e.g., the base of a sensitive transistor) making something act out of control, as you have there. So, the BCM being the only module providing power, ground and control voltage to the 4 relays, has got to be the culprit. Can't wait for Part 2 :-)
If it were my car and the part was that hard to get, I'd be opening the BCM to see if I could find the problem. Perhaps I could fix it. But there's also a good chance I'd at least see something wrong which assures me that this is the problem. Really, this problem doesn't feel like the computer itself, but I can believe that damage to the drivers could do it. In other words, this feels more like a green crusty problem than something requiring a logic analyzer.
Leaking capacitors rotting into the PCB on a 5 year old car? Possible but far less likely than with something a lot older. Green crusties otoh can happen to a brand new car. We went through a time when all capacitors in all products were suspect at any age. A whole mystery novel could be written about the cause of that one. Regarding Honda, this problem did attack my 1991 Acura in the ICU (intergrated control unit, 1991speak for a body module) causing the intermittent wipers to be...uh...intermittent. Then it went further and pretty soon you could turn on the left blinker and the right headlight would flash. 🤣🤣🤣I found a used ICU on EBAY, which was the only option at the time and it had the same problem but I was able o fix that one.
I have a good bcm out of a 2018 odyssey i can sell. Dealer warrantied the bcm but that wasnt the issue. My issue was the camera ecm in rearview mirror. I also have 2 injectors not working properly which causes a p0420 & p0430
Even if green crusties were turning on relays, the car should not start due to the immobilizer not present. So, does car start when all this turns on? Also.... how about pulling BCM fuse instead of battery every night, may be easier and cleaner to do. Hope the BCM solved the problem.
Remove bcm and supply powers and grounds, then put a test light on the ignition wires. Would eliminate all inputs and out side variables to see if the bcm turns on ignition circuit on it's own.
In the past, Honda outsourced clusters to Ford/Visteon. Remember a cluster that would heat load resisters to the point they desoldered and dropped from the board. Apparently quality wasn't Job 1...
If you could monitor battery current with a deep memory scope or logger and trigger at an amp above sleep current (with some pre-trigger data), you might see a current signature that could be used to understand a possible module sequence of events (current draw magnitude unique to each module or load). Maybe you could determine what module turned on first. My troubleshooting approach is much like yours, although having an electronic repair bench (microscope, soldering stations, etc.) available to me, I will take apart a suspect module and inspect it before replacing it. You can find uncommon failures and many times, if you have access to a electronics parts inventory (TH and SMT), you can fix the module if the problem is not related to a custom IC. An obvious failure mode is a cracked solder joint or PCB trace, and relay contacts if the vehicle is older. But many times you may have a single SMT component fail. For example, a stacked design SMT ceramic capacitor which can crack and fail short, open or intermittent. I keep a small inventory of the most common high reliability automotive chip capacitors (NP0 and X7R) with features like; soft end termination, AEC-200 Qualification, etc. in 0402, 0603, and 0805, with some larger values in 1206. I also have an inventory of automotive Tant and Polymer. If a find a bad SMT Aluminum Electrolytic I can usually order a good replacement part on-line. Through hole Aluminum Electrolytic Capacitors are relatively easy to buy.
Unplug the power lift control module that talks to the BCM and tells it to turn on accessory power (supposedly, I've actually seen it turn on the ignition) to activate the lift. if it's sending erroneous commands it could be triggering the BCM to activate
Verify that it is what's causing it, you can backprobe the circuit fuses when the issue is happening, if the bcm is the only module drawing current then you know that's it. You said some others have claimed similar issues. So I would discount a possible aftermarket accessory at fault.
Worked in the research division of a major American automaker on engines and transmissions. We didn't drive "modern" cars. We knew better. Enough said...
have a 2018 Ridgeline. same platform than Odyssey. I have similar electronic symptoms. intermittent clicking and flashing of infotainment. I removed the TPMS (Hondas name for BCM) and inspected it for cracked solder joints. Here in Canada they quoted me $1000 dollars for this module installed and was in backorder for at least 3 months. I said no. went back home. then gave it a good clean to the grounds of this module with electronic cleaner. Also, you wouldn’t believe it but also give it a good clean to the push start button. I have been problem free for 3 months. before this the alarm would go off at least twice a day and the cluster will start flashing and numerous relays would start clicking like a possessed car.
I think I know where that dent came from on the drivers front fender. I think it's called a frustration dent. I've witnessed a few a few of them in my lifetime. Can you disable the BCM, or disable the signal buss from the BCM and see if the issue still happens?
There maybe one component to blame,the start stop switch.When new hondas are delivered you have to place the key right next to the start stop switch in order to start the car.This suggests that the swich has a reciever in it.If the switch is faulty it could start the car.I believe its not just a switch,its a complicated component.Other honda models suffer from failure of this switch.
Yeah I agree parts especially one containing logic boards have been hard to source. Leading to more eeprom work. But on that note would live to see what's inside that BCM Making it go crazy 🤪 maybe corrupt firmware or logic? Or ? Hopefully we could get to see a "no parts needed" fix! Lol. But seriously this is an interesting case study. Thanks fir sharing!
I've seen that issue too.. Rather than getting a new switch, we just bypassed it so that it always thinks you're in neutral/ park. But that's not going to randomly turn on your ignition.
My wifes grand mother has this same car with the same issues and more. It will roll down the windows, open the sunroof, the radar sensors always alerting. Has been to honda dealerships a million times.
I had a similar case study. The dash would light up but if I took a test light and applied it to the fuse that had voltage everything went out. It was enough power to light the leds in the dash but not enough for a test light. I traced it to a Bluetooth module right next to the hatch back. The module was covered in water. The main power wire was corroted to the ignition on wire. Even when unplugged it still stayed on until I pepinned the connector. They actually auction the car because of the issue. The only difference is I dont think everything came on (radio ignition and so on). This was about 3 years ago on a 2017 and I don't even remember the model.
I'm not sayn this is your Honda's issue, but my 05 TL had a strange battery draw no start, no crank issue that wouldn't let the cluster go to sleep.While I thought it was the BCM, it ended up being the transmitter control module, which also controls the key fob signal, and programmable garage door opener etc. Pull that fuse, and the draw was gone, and the cluster went to sleep. Note that there were no codes. Note, that by pulling said fuse, no interior door lights work, no fob functions, but the car will still see anti theft signals from the fob, and the interior power trunk still works. So does the all door lock unlock function with the door key used. I can't figure out how Acura is separating all this, but i can at least run the car normally.
Worked for Honda for many years reached master after 5 years and I came across this ended up being the module but I spent hours trying to figure it out. Sometimes the best we can do is give a estimated guess.
I think the BCM is going into a fail-safe mode because it's detecting an issue it doesn't like. From what I understand, the default state for these BCM-controlled systems is the "ON" position. I looked at the wiring diagrams, and the pushbutton switch appears to push one circuit high, and the other to ground. If the circuit states don't match what's expected, this may be the root cause of the problem. It's also worth noting that a 10-amp fuse feeds the pushbutton and one branch to the BCM. If that circuit drops out intermittently, possibly that's the cause of the problem. Maybe water or some other drink got spilled on the pushbutton and is causing an internal short. I'm assuming that the BCM doesn't require a valid proximity key be present to enter the fail-safe mode.
Hey Ivan why can't you just get the bcm from the salvage yard for $100 or less . That's what we do . We never have any issues with the used parts we get and the customers are happy with a used part .
It has rained and water has got into a connector or module. I had such a problem which took the main dealer a whole week to fix. I can hear the water on the ground whilst you are walking
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I've had a very similar case study like this one. 2003 escape. Ultimately came down to finding that the instrument cluster had a bad diode, leaking voltage into the ignition power circuit that backfed the control side of a relay keeping that relay latched, providing power to the vehicle keeping the vehicle running. my move is exactly what you're doing in the bonus footage. These ones are always a challenge lol. (I actually ripped apart that instrument cluster and replaced the smc diode on the board and got the customer their car back vs throwing in a reman or used. pretty sweet)
Wow you certainly know your stuff but how many hours labour did you spend doing that.
@@deniscarr469 Very, very good point. If my memory isn't crap, 2-3 hours to narrow it down to the cluster. Then about 30min-1hr testing on the board and fixing it. Luckily the diode had a witness mark so it was easy to tell where the magic pixies went 🤣 add another two hours for a trip to fry's electronics (may they rest in peace) and reassembly. Definitely didn't charge them enough to cover a whole day project. Think I did diag, an hour for r+r, and $100 for the cluster fix. Eh, you win some, you lose some. Lady still comes back to see me every time she's got a problem though. Hard to come by in a woman, loyalty. 🤣
Give it an exorcist. Walk around the car screaming: Get out of this car, the power of Chrysler compels you.
Underrated comment here folks. Well done. Hahahaa.
This or get another one there and beat the everliving crap out of it. Then say and you're next if you don't stop it! "Stupid smart cars..." indeed.
LMFAO...ROFLMAO
Maybe a catholic priest can intervene
The car gave the owner a Fiat
Hello Iven, i smiled and clicked your video as soon as i saw the thumbnail! A new BCM will fix this car, i've been through a 2018 elite with the exact same symptoms and that was the fix. I am actually surprised it only took you an hour to reach that conclusion hence it took me a full day to make the call 😅. You are an excellent tech, and i am glade you decided to share your knowledge with the community. Good luck
I love how the owner detected when it powered up by itself using the loud radio. Pure genius!
Hey Ivan. I ran into this same problem with a 2017 crv a year ago. The BCM was unavailable.(still isn't) That really sucks for the customer. I even opened up the module to inspect for a possible manufacturing error. Found nothing. I do automotive electrical and diagnostic work for a living, and your right, the newer these cars get, the harder it is to find modules should they go bad. Good luck with your odyssey. My temporary solution was a constant duty solenoid to power up the micu/BCM.
This is not an isolated instance, other Honda owners of similar age models (e.g. Civic, Pilot, CRV) have experienced the same symptoms and have either had the BCM replaced or are waiting for them to become available. There are a few people saying the keyless entry module was the cause, this is much cheaper and available so may be worth a look.
The transmitter control module went bad on my Acura, and caused similar issues
As a Honda Technician, if we have a vehicle that powers itself on by itself (usually also comes with intermittent alarm), and we see the gauge cluster turned on with the key nowhere near the vehicle, we know it's a BCM issue. Also for IGN1 alarms where the car sets off its alarm randomly by itself. On some models its the keyless entry instead of the BCM, but I believe that's really only on the Pilots. Basically whichever module controls 'turning on' the car when the start button is pressed, is the culprit.
I had something like this on a 1981 Ford Thunderbird Heritage Edition. This car had the electronic dashboard and things I had never seen in a car before. The interior lights and the dashboard were coming on by themselves. Now, this is long before any modern electronics or canbus or anything. I had a repair manual that was for the electrical and it contained flow charts. I messed with that thing for 2 days. It would be sitting outside and the interior lights would come on and the dashboard would light up. Turned out to be a bad lighting control module that was backfeeding through the ignition. This video reminds me of that. Great video!
Ive seen this befor on my friends 2015 Colorado, he didn't fix it and problem got worse , eventually got to the point of engine starting and running by itself.. He had a rear leaking window that sometimes caused alot of moisture inside and I figured that may have somehow ruined the bcm. Replaced BCM and he hasn't had any problems since. So i believe you made the right call PH.
Miss the good old days when you could climb into the engine compartment to do repairs, actually see the spark plugs before you remove them, change a headlight for 5 bucks and a tail light for 50 cents, 7 dollars for a wheel bearing instead of 250 for a hub assembly.
The good old days when head lights had the brightness of a firefly in a mason jar, a 5.7l v8 made 120hp, a mid size family car got 14 mpg, and if you hit anything you were instantly killed.
@@JackS425 you know it
Amen.
@@JackS425 Yeah, good old days when $1/hour was a good wage.
Welcome to 2022 and new technology
This seems very similar to an issue my dad had with his 2018 Ridgeline. Honda has a service bulletin to replace the keyless access control unit. The alarm would also go off for no reason at times. Parts were not available for the ridgeline, the dealership turned off the smart lock feature and the issue has not returned.
I'm curious to know, if the brake pedal was held down would the car actually start? Time for an experiment
@@soundman6241
I don't think so. It has been a few months ago. After the auto lock feature was turned off, everything worked normally.
I own a 2018 Odyssey with almost identical symptoms including the weird “lost power to alarm..” message on screen. It is very intermittent but the car has left me at least 5 times with a dead battery. I’m in SoCal and car has
Must be infuriating. Just out of warranty.....or is it? Is there dust in or on the connections? Maybe a lot of thieves are just driving around trying codes or seeing whose lights come on. Maybe drive in a different area.......
2019 Honda Odyssey elite 90K milesl, so initially, the Lane detection camera ($700 part) has been bad, but I have been driving it anyway for months buying time. However, now the car will not shut off? I think it is unrelated to the many lane camera error messages. I had to pull the battery cable off to stop the engine; then it that reset computer (?)and it started it fine, seemed ok. Locked it up and went to bed only to wake up to the horn alarm going off later! The key remote didn't work to turn off the alarm!. So I had to use the 'real key' inside the fob to open the door the old fashion way. I found out if I don't lock it the security system won't go off like that. However, the accessory power still comes on by itself!! I caught it twice but now my battery is dead or drained from the accessory going on. I see other's pointing to the ignition switch as the cause. I will update.
This reminds me of a similar case I had with a 2015 BMW F20 1 series. The fuel pump would start running full speed at random when the car was parked and should be asleep. Eventually causing the battery to be discharged over night.
The fuel pump is controlled by a fuel pump control modules that regulates the fuel pump speed based on fuel demand coming from the engine control unit. A BMW dealership already replaced the fuel pump control module to no avail.
When it came to me I knew that the fuel pump should only be running at 100% if the fuel pump module is awake but has no communication with the engine control unit. Looking at a diagram it has a wakeup line. When it was acting up the wakeup line was raised to 12v thus waking up the module even though the engine control unit wasn't requesting fuel flow, causing it to start running at full speed. Looking at the diagram I disconnected every module on that wakeup line one by one and determined the FEM (Front Electronics Module, basically like a BCM controls everything like ignition, lighting, power windows, door locks, starter relay etc. ) was outputting 12v on the wakeup line when it shouldn't. I was ready to call the FEM until I found not a single used unit with Comfort Access like the car had and a new one from the dealer was way out of the customers budget. With that in mind I decided to dig a little deeper. When it acted up again I started removing connectors from the FEM one by one and noticed when I pulled 3 specific connectors out of the 10 that were connected to the FEM the fuel pump turned back off. Looking at pinouts for those connectors nothing looked really interesting except for a wakeup line going exclusively to the instrument cluster. I had noticed that when the car acted up the indicator lights on the cluster would light up. And what do you know, when pulling the pin for the cluster wakeup line out of the connector and reinserting the connector into the FEM the fuel pump remained silent. I reinserted that pin and just disconnected the the connector at the back of the cluster. Left the car for 2 days and 2 nights. Battery wasn't drained while it would be dead every morning cause of the fuel pump issue. Got a used instrument cluster, virginised it, programmed it to the car and the problem was solved. Sometimes you've just gotta know how the system works and dig a little deeper even though the answer looks straight forward. It might not be.
Great diagnostics process 👌🙂
Your event gives credence to fears of artifical intelligence going amok.
It is always an 'adventure' when you share your troubleshooting. And you always seem to encounter the most perplexing of problems.
Hi Ivan.You're making the right call in the circumstances. Financially it's a no brainer - change BCM. From the customer's point of view he/she could end up paying for hours and hours of diagnostic time for no result.
Ivan good call.(maybe)
In the early 1980s Volvo had a similar problem with the Volvo 340 CVT model.
If you left the car and closed the drivers door sometimes the car would start and if you left it in
gear the car would start up and drive away !!!!.
They introduced and new fuse box( now called BCM) and a different gear lever with a buzzer fitted to try
a warn people to not leave it in gear.
Hi Ivan, I've been working in the field for 15 years and for the last year I've been watching all your videos, I've learned a lot and I apply it in my work too, you help me a lot, thank you. Your videos are great and I always watch them with an interesting, healthy and very happy look. Greetings from Israel :)
All the symptoms are pointing to a problem at the BCM. Either a faulty connection to, or a faulty module itself. It is really difficult to tell at this point, but I can't argue with your hypothesis either as it does seem that the BCM is the most probable suspect. Something that caught my attention though was, there is an "updated" part listing for the BCM on a 5-year-old vehicle. Not an identical replacement part. And no related TSB's on it. Just something that makes you go humm? I am looking forward to part 2.
Odysseys, Pilots, Ridgeline, CRV and Civic all could have this issue. Correct with BCM diagnosis. Check alarm history and see if "ignition switch" was a alarm trigger. It's usually a good indication of BCM ghosting ignition to run position. I have waited over 8+ months to get BCM from Honda. Try and source a used unit. Be sure parts numbers are correct. They have different part numbers for different trim lines in the same year. As far as I know they are not flashable to different trim lines. Good content Ivan. Thanks,
Hey. Great video...my 2013 Honda Pilot 55,000 mi also was possessed. Navigation and radio constantly rebooted, headlights flash, close object warning flashes. All without the key present...and it would not start ...$2300 later it was a bad micu and 2 shorts in the wiring harness. omg
BCM Is the correct educated guess, I'm seeing this issue more often lately. Only dealer tool will be able to program the new BCM/Used. There is no flashing for the New or used BCM only immo needs to be learnt, Original keys can be reused. Used Bcm with same part number can also be used.
I've seen this once. The owner put a spare key in a magnetic hide- a- key under the car. After market ebay key of course...... It would get wet and yup! Took weeks to pry that info out of customer.
My 2014 Ford F-150 has the ECU (electric control unit) turns lights and ignition on and drains the battery overnight. I have had it to the dealer under warranty numerous times and they can't find anything wrong. It is a fairly common problem with Fords but the dealers won't acknowledge it. You are correct in your assessment of "stupid smart cars" I work on classic cars, points, plugs and condensers. And I can fix things not just throw parts at a car like the dealer techs do.
We fixed a couple pilots doing that At the dealership those two pilots would also sound the alarm of course conveniently at 1 o’clock in the morning lol
BCM was faulty? What year?
@@PineHollowAutoDiagnostics 17 Pilot Elite Smart power control unit module and I miss spoke earlier it was a 17 or 18 Ridgeline. Smart power control unit. I didn’t look at our interactive network site I’m not sure if odyssey even uses this module but it certainly affects pilots I believe even a civic it would just turn the key on and sometimes you could not even turn it off with the button but I could be off Mark on this one I’m not sure if that Odyssey uses the smart module or not On the pilot it’s on the passenger side flip down the glove box mounted with one bolt below the airbag.
Intermittents are such fun! I've had them before, some take many days to locate. The wiring diagram was
the main helper along with one DMM and one Fluke 98 scope in DMM mode.
No green crusties, but a lot of heat related problems that caused the Intermittents. A heat gun sometimes helped.
You'll find it.
With a computer involved, anything can happen. All it takes is a tiny leakage current to common in a capacitor tied to a processor input normally pulled high, or a switch mode power supply or power converter with too much AC ripple. Somewhere, there is a logic 0 or logic 1 that turns on the ignition, and whether that tiny signal should be high or low, it doesn't take much to change it. I think you get these cases because of your superior intellect and logical thinking.
Well, at least we all now know why the dealer recommended a new tail gate module. They knew they couldnt get a BCM. lol!!
Agreed!! In this case I would say the bcm has for whatever reason has said see ya. Looking forward to part 2.
Part of me would wonder if there is a key hiding somewhere. I’d delete out any keys but what you have, Just in case. There should be an encryption code shared between the ecm/bcm for each key that should be needed to power up the car. Replacing the BCM should invalidate the keys, and would also cause the same outcome.
It will be interesting if you can pair the bcm/ecm or if a dealer will have to do it.
The car would be able to start if there is another key inside, and it can't.
I had found a set of fobs with factory build sheet while detailing my Chevy truck. They were between upper back seat and cab wall. I saw a little piece of plastic hanging down and didn't know what it was until I kept pulling at it to get it out.
I feel your pain on Honda parts availability. My sister-in-laws 2018 Fit was rear ended in late December 2021. Took until August 2022 to get all the parts to repair it!
You know Ivan, putting a kill switch wired to the BCM would be a cheaper solution to the problem AND I think also a great theft deterrent. If a crook steals the FOB RF signal, there will be no way in hell they could steal the vehicle. I know push button start and theft is a huge problem for Toyota but all push button start cars are susceptible.
Keyless access module. We’ve seen a lot of them on the Acura side. If the alarm was set, the alarm would go off and store a “IG1” as the trigger device.
You mentioned adding a switch. How about turning off the Batt supply to the BCM? Maybe try that as a test first? Hoping to see a solution in part 2. Thanks for this part.
I haven't read all the comments so don't know if this was asked/answered. Thinktool is powerful .. maybe try re-initializing the BCM right up front, before anything else?
I never heard of that tool before.
Ivan, you have us as perplexed as you must be feeling right now. Just changed the oil in my 97 Dodge Truck and 02 Caravan. Can't say I'm really ready for what the automotive future looks like right now. Hope to get a some more time on the vehicles I have now. Trick or Treat? Thanks for Sharing!
Guided parts cannon.... Not just the parts cannon. Big difference! But agreed, what else could it be what actually controls the keyless and starts that car?
YOUR ON THE RIGHT TRACK HAVE MANY WITH THIS ISSUE, ALWAYS A DIFFERENT ISSUE, INTERMITTENT, OR STAYS ON ALL THE TIME AND KILLS THE BATTERY. OUR ALARM GOES OFF. THE BCM HARD TI GETS TO ABOVE THE FUSE BOX, WHICH HAPPENS ACROSS ALL HONDAS NP TSB FOR THIS
I had a crv a while back that was a parasitic draw. This new town i moved into has a big problem with draws. I went 6 years as a tech in my hometown and only ever had 1 parasitic draw that was something real easy that i have forgotten what it was. Here I've had like 5-6 cars with draws in the year i have lived here. Anyways this crv at first I found the radio was staying on. My draw went away when I unplugged it so I replaced the radio. Supposedly that wasn't the fix when the customer returned about 3 months later saying he was still having a dead battery. It then took a few visits to the shop because he would need the vehicle to get to work and couldn't leave it for any reasonable length of time but I finally found that the MICU/BCM was actually the issue and was keeping the Radio on at all times. I dug deeper when I found that new radio was staying on again. Lesson learned. Anyways all that to say that the BCM for that car took 5 months to get and same thing I think it was a 2015-2018. Somewhere around there
Apparently Honda has the biggest problem with parts...buy an alternator while you can get it - you'll need it.
Great work Ivan and looking forward to part B:)
I agree with your diagnosis but one problem I see is that let say the bcm is (seeing the key ) and turning the ignition on. I would think the car would start when pressing on the brake and pushing the start button when the ignition is on. Also I noticed what appears to be the red security light flashing on the cluster when the ignition comes on. I’m not disagreeing with you but It would be hard to call it the bcm when the fuse box could cause this too. Only way to tell is to isolate the ignition control feeds from the bcm to the fuse box. I enjoy your videos
I had a 2019 Honda passport, all kinds of electrical issues. I had same issue as well as the vehicle would brake on its own, accelerate on its own. Rear tailgate opened with no command. Radio was an issue with noise, the dealer would do noting for me. I had less than fifteen thousand kilometers on it. Never solved it and got rid of it.
Wow what a lemon lol
Love it Ivan!" Stupid smart cars" and cannot open the rear sliding door.
Nearly a year ago our Ford had a problem. Towed to a dealer and waited a month for parts. Corporate said they don't have an ETA for parts and, at the time, the dealer said he had about 10 cars waiting for parts. Had to purchase a new car. Fortunately, a dealer gave us book price for our non-running, but warrantied car. Are we still blaming covid for this?
Great video. Thanks
the fact that their is a updated bcm makes a lot of sense
Yeah when you see a revised part and it’s also backordered it’s usually a telltale sign something is up.
Try resetting the bcm by disconecting both positive and negative on battery and take 1jumper cable and connect positive and negative leads to engine together for 20mins and do these steps in reverse and bcm should go back to factory default settings, therefore fixing your problem. U r welcome.
What was so difficult about putting a key in a hole and turning it to start?
The systems with a chip in a proper key were probably the most secure and reliable in my opinion.
Go ahead and change the bcm, and trust your work, and yes cars are becoming disposable items!, I hate this start stop gizmos. Looking forward to the next vid
just started watching... perhaps one idea would be to do a full scan without turning the ignition on when the car acts up. just to se what if any modules is responding... to se what modules got power and narrow it down that way.
I would try to scope between BCM, ignition key on.
See what's happening, what kind of voltage drop is going on there.
Other idea is to look at salvage yard, take kne from there if you can find 2016-2018 Honda Odyssey Elite
What if the bcm is faulty triggering the key on but the relay switch is stuck on continuously giving ground making it so only one faulty signal is needed to make bcm think key is in proximity.
Does the car have "On-Star" type capability that can remotely start the car (without the key being needed)? Maybe that system has gone haywire. Also, I noticed a big dent on the driver side front fender. Maybe the car was in an accident and some wires got got messed with? Looking forward to Part 2, Ivan!!!
What device actually reads the presence of the key inside the vehicle? Is that device directly connected to the ignition button? My thought is if those two items are part of the same module behind the dash, then the BCM could be ok and that button-and-antenna module could be telling stories to the BCM. On the other hand, if they're completely separate, then it's more likely to be a fault in the BCM itself. Guess we'll see in part deux.
BCM is a well educated guess, maybe keyless entry module, did not look like it had any aftermarket remote start installed. Now you just have to find one, possibly reprogram a used one ?
I am curious as to why the dealer blamed the liftgate control module. That is a module that should have power at all times. Could it be feeding power back into the BCM? Seem like it would be a simple test to disconnect the liftgate control module when the car is acting up and see if the power to the cluster goes away.
Bcm/keyless access module common on these Hondas and Acuras to cause this same problem as well as other problems. Keyless access module is part of the bcm on this Odyssey. Alldata has good info on the system description of the keyless access system, there is no literature of your issue, but it’s common and yes the bcm has been on back order for a long time
Unfortunately, my wife's 2017 Honda CRV is doing exactly the same thing. I watched both part 1 and part 2 of your diagnostics on the van. How is it possible that a vehicle with a proximity key starts itself without the key being present? Exactly what her CRV is doing. It only has 33k on it. Sadly, it's out of warranty because it's a 2017. I have no idea how much money this is going to cost to get it back up and running. Thanks for the video. Much appreciated 🙏
Good luck. New Hondas can suck sometimes lol
I would disable the keyless entry and remote start. You had a issue with door locks and power doors. Dealer had reason to fault rear hatch that may also be keyless entry fault.
Hey Ivan, if needed I could send you an install guide for the add on remote start units that are basically plug and play. I have seen this same problem with a push to start Accord that turned out to be a faulty remote start. Also try pressing lock on the factory remote 3 times. If it has an add on remote start this should activate it.
Yeah, it's gotta be a remote start issue. Nothing else should be physically able to do this, this way.
Checking for a remote start add-on is an great idea.
I think replacing the BCM is a good call. We had a similar problem on one of our 2016 F-150's. At random the DRL lights would come on and there was about a 20 amp draw when it was acting up with nobody inside key out and doors locked. I messed around with it and we ended up taking it to the dealer. They had it for about two months and the mechanic traced it down to no bulbs in the cargo light. The upfitters removed the bulbs when they installed the cap and he said the BCM was searching for those bulbs, couldn't find them and was acting up. There was a code for the puddle lamps. It fixed the problem when he pet the bulbs back in
Ivan, I still drive a 95 Honda passport/ Isuzu rodeo. 325k on original motor and transmission. I changed the plugs recently and decided to check compression. 170 psi on all cylinders. Last emissions test HC was 21 and CO 0.01. I've beat the piss out of it in the mountains hear in Boise. I just maintain it really well. Got lifter noise, but what 3.2 dosent. Lol
That's a cool truck. Respected durable 4x4 in the Russian boonies too 😀
The sliding door not opening might not be "stupid smart cars", but a very good clue. I'd troubleshoot that, as it might lead you to the main suspect; the BCM😊
Or turn off the child lock switch
We had a BMW that would just spontaneously lower all the windows. It especially happened within 5 minutes of parking the car. Sometimes I would turn the car off in a parking lot, get tied up on something before walking away too far, suddenly hear a whir, "What was that?" Go back to the car and all the windows were down. Other times I would return from the store only to find all the windows down. And it was raining.
I had a VW Jetta as a loaner that actually had a warning in the manual that the door handle touch pad could actually trigger the "feature" to lower all the windows if you hit it with a car wash spray in just the right pattern. You'd think they would have clued in that this indicated that "feature" wasn't thought out very well..
Bad BCM, had that on 2020 civic
Upd on the tap on bcm - if you crack bcm open youll find overheating signs on the main mcu, i believe its RH850 from renesas, if not mistaken
Honda possessed by devil 😬
Who you gonna call ? Pine Hollow Ghostbuster 😂
Your guess is just as good as mine..
Seen so many of these on Acuras, used to work at the dealer. Ends up being the Keyless Access Unit (some have TPMS built in) or BCM on the newer cars. I'm not sure if you can check with other scan tools but if you check with the HDS, in the Body Electrical > Security history. It will have an alarm trigger by the Ignition Switch.
Supply for parts for almost everything is terrible. So curious about the back story on the banned from the dealer thing. Funny.
when that Honda is parked there is a gas tank purge valve that depressors the gas tank some times they stay on , it works to depressor the gas tank even when the engine is off lol
You have a thing for weird cases, Ivan :-) It seems like a very educated guess to get a new BCM!
IMHO, a leaking capacitor can bridge tracks of a PCB and pass low current intermittent signals where they shouldn't go (e.g., the base of a sensitive transistor) making something act out of control, as you have there. So, the BCM being the only module providing power, ground and control voltage to the 4 relays, has got to be the culprit. Can't wait for Part 2 :-)
If it were my car and the part was that hard to get, I'd be opening the BCM to see if I could find the problem. Perhaps I could fix it. But there's also a good chance I'd at least see something wrong which assures me that this is the problem. Really, this problem doesn't feel like the computer itself, but I can believe that damage to the drivers could do it. In other words, this feels more like a green crusty problem than something requiring a logic analyzer.
Leaking capacitors rotting into the PCB on a 5 year old car? Possible but far less likely than with something a lot older. Green crusties otoh can happen to a brand new car. We went through a time when all capacitors in all products were suspect at any age. A whole mystery novel could be written about the cause of that one. Regarding Honda, this problem did attack my 1991 Acura in the ICU (intergrated control unit, 1991speak for a body module) causing the intermittent wipers to be...uh...intermittent. Then it went further and pretty soon you could turn on the left blinker and the right headlight would flash. 🤣🤣🤣I found a used ICU on EBAY, which was the only option at the time and it had the same problem but I was able o fix that one.
Once you get a reputation that proceeds you, stuff like this becomes the normal....
@@additudeobx I can say from experience that you are correct.
@@InsideOfMyOwnMind Water in the ECU could do much the same.
I have a good bcm out of a 2018 odyssey i can sell. Dealer warrantied the bcm but that wasnt the issue. My issue was the camera ecm in rearview mirror. I also have 2 injectors not working properly which causes a p0420 & p0430
Even if green crusties were turning on relays, the car should not start due to the immobilizer not present. So, does car start when all this turns on?
Also.... how about pulling BCM fuse instead of battery every night, may be easier and cleaner to do.
Hope the BCM solved the problem.
Remove bcm and supply powers and grounds, then put a test light on the ignition wires. Would eliminate all inputs and out side variables to see if the bcm turns on ignition circuit on it's own.
OOOOO bete wah bete wah moj krde tune toh bade heavy driver ho bahi tum toh !! In the end Very good Diag Ivan appreciated it buddy!
In the past, Honda outsourced clusters to Ford/Visteon. Remember a cluster that would heat load resisters to the point they desoldered and dropped from the board. Apparently quality wasn't Job 1...
Did Ford design the module? How do you know it's manufacturing and not a design issue? Oh..I know, anything to bang on Ford...got it...
If you could monitor battery current with a deep memory scope or logger and trigger at an amp above sleep current (with some pre-trigger data), you might see a current signature that could be used to understand a possible module sequence of events (current draw magnitude unique to each module or load). Maybe you could determine what module turned on first.
My troubleshooting approach is much like yours, although having an electronic repair bench (microscope, soldering stations, etc.) available to me, I will take apart a suspect module and inspect it before replacing it. You can find uncommon failures and many times, if you have access to a electronics parts inventory (TH and SMT), you can fix the module if the problem is not related to a custom IC.
An obvious failure mode is a cracked solder joint or PCB trace, and relay contacts if the vehicle is older. But many times you may have a single SMT component fail. For example, a stacked design SMT ceramic capacitor which can crack and fail short, open or intermittent. I keep a small inventory of the most common high reliability automotive chip capacitors (NP0 and X7R) with features like; soft end termination, AEC-200 Qualification, etc. in 0402, 0603, and 0805, with some larger values in 1206. I also have an inventory of automotive Tant and Polymer. If a find a bad SMT Aluminum Electrolytic I can usually order a good replacement part on-line. Through hole Aluminum Electrolytic Capacitors are relatively easy to buy.
Had it been in an accident? I did notice a dent.
Unplug the power lift control module that talks to the BCM and tells it to turn on accessory power (supposedly, I've actually seen it turn on the ignition) to activate the lift. if it's sending erroneous commands it could be triggering the BCM to activate
Verify that it is what's causing it, you can backprobe the circuit fuses when the issue is happening, if the bcm is the only module drawing current then you know that's it.
You said some others have claimed similar issues. So I would discount a possible aftermarket accessory at fault.
Worked in the research division of a major American automaker on engines and transmissions. We didn't drive "modern" cars. We knew better. Enough said...
have a 2018 Ridgeline. same platform than Odyssey. I have similar electronic symptoms. intermittent clicking and flashing of infotainment. I removed the TPMS (Hondas name for BCM) and inspected it for cracked solder joints. Here in Canada they quoted me $1000 dollars for this module installed and was in backorder for at least 3 months. I said no. went back home. then gave it a good clean to the grounds of this module with electronic cleaner. Also, you wouldn’t believe it but also give it a good clean to the push start button. I have been problem free for 3 months. before this the alarm would go off at least twice a day and the cluster will start flashing and numerous relays would start clicking like a possessed car.
reprogram the BCM may clear a logic error assuming not bad relays in it. open bcm look for water damage?
I think I know where that dent came from on the drivers front fender. I think it's called a frustration dent.
I've witnessed a few a few of them in my lifetime.
Can you disable the BCM, or disable the signal buss from the BCM and see if the issue still happens?
my same thought
the first thing i would check is if an aftermarket garbage remote start was installed, after that the BCM seems to be the culprit for sure
I agree, it's gotta be a remote start issue.
One of the first crazy ideas i had looking at this, is what if one of the owners lost the second key somewhere inside the car...?
Would it not turn on the BCM all the time rather than intermittently?
Is there another key flob in the vehicle somewhere dash under the seat.
There maybe one component to blame,the start stop switch.When new hondas are delivered you have to place the key right next to the start stop switch in order to start the car.This suggests that the swich has a reciever in it.If the switch is faulty it could start the car.I believe its not just a switch,its a complicated component.Other honda models suffer from failure of this switch.
Hi... humidity!!!!?
Keep in mind mostly Water or cok or coffee dripped over in electronic system
Yeah I agree parts especially one containing logic boards have been hard to source. Leading to more eeprom work. But on that note would live to see what's inside that BCM Making it go crazy 🤪 maybe corrupt firmware or logic? Or ? Hopefully we could get to see a "no parts needed" fix! Lol. But seriously this is an interesting case study. Thanks fir sharing!
Hi Ivan, have you checked that the spare key is not in the glove box, or under the seat etc?
You might want to check the switches to the shifter, we had a honda that the car would think it was not in park due to a faulty park indicator switch.
There is no shifter... It's all buttons and modules 😂
I've seen that issue too.. Rather than getting a new switch, we just bypassed it so that it always thinks you're in neutral/ park. But that's not going to randomly turn on your ignition.
That may keep it from turning all off the way off or starting but it wouldn’t cause it to randomly turn on.
My wifes grand mother has this same car with the same issues and more. It will roll down the windows, open the sunroof, the radar sensors always alerting. Has been to honda dealerships a million times.
I had a similar case study. The dash would light up but if I took a test light and applied it to the fuse that had voltage everything went out. It was enough power to light the leds in the dash but not enough for a test light. I traced it to a Bluetooth module right next to the hatch back. The module was covered in water. The main power wire was corroted to the ignition on wire. Even when unplugged it still stayed on until I pepinned the connector. They actually auction the car because of the issue. The only difference is I dont think everything came on (radio ignition and so on). This was about 3 years ago on a 2017 and I don't even remember the model.
Had the same problem with my 2017 civic EX T. It was the BCM.
I'm not sayn this is your Honda's issue, but my 05 TL had a strange battery draw no start, no crank issue that wouldn't let the cluster go to sleep.While I thought it was the BCM, it ended up being the transmitter control module, which also controls the key fob signal, and programmable garage door opener etc. Pull that fuse, and the draw was gone, and the cluster went to sleep. Note that there were no codes. Note, that by pulling said fuse, no interior door lights work, no fob functions, but the car will still see anti theft signals from the fob, and the interior power trunk still works. So does the all door lock unlock function with the door key used. I can't figure out how Acura is separating all this, but i can at least run the car normally.
hey Ivan can you use your thermal imager to look at any heat signatures?
Not sure what I would image though 🤔
kill switch will work, very nice explanation, did you check for any aftermarket stuff...it happens to me In a Toyota tundra (aftermarket immobilizer)
Worked for Honda for many years reached master after 5 years and I came across this ended up being the module but I spent hours trying to figure it out. Sometimes the best we can do is give a estimated guess.
Educated guess.
I think the BCM is going into a fail-safe mode because it's detecting an issue it doesn't like. From what I understand, the default state for these BCM-controlled systems is the "ON" position. I looked at the wiring diagrams, and the pushbutton switch appears to push one circuit high, and the other to ground. If the circuit states don't match what's expected, this may be the root cause of the problem. It's also worth noting that a 10-amp fuse feeds the pushbutton and one branch to the BCM. If that circuit drops out intermittently, possibly that's the cause of the problem. Maybe water or some other drink got spilled on the pushbutton and is causing an internal short. I'm assuming that the BCM doesn't require a valid proximity key be present to enter the fail-safe mode.
Hey Ivan why can't you just get the bcm from the salvage yard for $100 or less . That's what we do . We never have any issues with the used parts we get and the customers are happy with a used part .
It has rained and water has got into a connector or module.
I had such a problem which took the main dealer a whole week to fix.
I can hear the water on the ground whilst you are walking
If Keith hasn't heard of it you know it's a good one