Is that sort of like the old Redd Fox story about the woman smelling the ducks asses in the Supermarket to tell where they are from---when she asks Redd where he is from--he bends over and say's to her "you tell me". LOL
Finally someone on TH-cam from New York State, and not Florida or the West coast! Wish I can bring my car over there, a good mechanic who is honest is a dime a dozen and here in buffalo there even rarer
I have worked in the high tech world of computers for 20+ years and your logic and methodology of diagnosing the issue was the same we use to resolve similar issues. Great Video.
Hey I just grabbed one of your videos to say you are awesome! 65 an hour you are dirt cheap and one of the best in diagnostics I have seen. Short of my hs shop teacher!! lol Thanks so much for everything you do and for putting it out for the world to see!
I gotta tell ya i love this channel it is simply entertaining and very informative ...and it shows what a “Real Mechanic” should be ..highly trained and exceptional at his craft...thank you for the video...
I love the sound of the noon whistle. My little town blew the fire whistle at noon and two surrounding towns blew theirs at 6 PM. BTW, I tuned in hoping for another brake job video. I actually like watching them and the parts changing videos.
Hey Eric - another great video. Also wanted to say I’m new to your channel and I’m hooked. I’ve been binge watching your old stuff nonstop for the past week. Absolutely love watching- you’re so thorough and I always learn something. You also have a wonderful family, and I find your “distractions” entertaining and usually really funny. Love the “toots” and “boogerd threads”. You’ve got the most informative and also entertaining automotive repair videos out there (I still feel this way even though I own two Audi’s and a VW - I know you hate working on them!). Sorry for the long post, but I just had to share my appreciation!
Thank you for opening a tool website. I am always adding/replacing tools and I will definitely be buying from it to show my gratitude and support for the outstanding videos you produce. I am happy I found your videos.
Great video. That was an awesome diagnosis and quick repair. Those cameras are a pain and I seriously doubt if a junkyard has a good one. They seem to have a life expectancy of about five years. Thanks for the video!
I use a flat screwdriver and a cloth to remove the taillight. I put it in the gap in between the plastic lens and quarter panel and wiggle it back and forth. No chance of damaging it from yanking it off. Works great for the stubborn ones.
i went to check the price for that rear trim with the camera.... MAN $300 bucks for it! OUCH at that point yes i can definitely live without a camera, great video again Eric! cheers!
You are right about the bulbs. In the mid 80s, I think 85, on New Year's night, after ringing in the new year, I got in the car, started it, turned on the headlights, and both flashed and went out. Clicked high beams, had them. Low beam, dead. What can it be? Bad switch? Bad relay? Ground? I thought surely it can't be, but I went the next day and bought 2 new sealed beam headlamps to replace the aftermarket halogen ones I had installed a little over a year earlier. Had low beams again. Check the bulbs first.
Thank you, thank you, thank you. I run into this kind of stuff quite often while doing used car safety checks. I try to explain to my boss that spending some time and pinpointing the actual issue is much more cost effective then shooting the parts cannon and hoping for a hit. ( some guys just don't get it). I have found that with some vehicles you can graft in an aftermarket back up cam and get it to work with the stock system (not my preference but it can work) at a much lower cost then the factory cam. But this video (going to make my boss watch) will save my bacon from yet another heated discussion with the boss man. Thanks my friend and keep up the great work. L&R to you and the crew at SMA....
Diagnosing a problem can take a lot of patience and a lot of time. Some guys just don't wanna wait that long before they start turning screws and swapping pieces.
Oh crap, now I have to watch to the end to find out what this issue is. That burnt up electrical smell is unique and it does work to diagnose electrical components. I've done the same thing many times.
I was able to do the same to my vehicle after seeing this video. I wasn’t sure about taking the panel off, but I did it. Now my back up lights and license plate lights work . Thank you
The field-effect transistor is an electronic device which uses an electric field to control the flow of current. FETs are 3-terminalled devices, having a source, gate, and drain terminal.Wikipedia
Always a great informative video. I’ve learned to always start with the easy stuff. Many times I’ve forgot and went off what a customer said instead of being smart.
As a computer tech for 15 years, it tickles me to see someone else use T-pins as tools. I used them far more times to probe or pick things apart then I ever did to put things on my cube wall. They are phenomenal as tools!
Boy!!! Do you ever make it look easy to find the problem in the electrical system. But hey, when you been doing for so long, you get to the point that you know what your looking for. Nice video, Eric....
Seriously, though, great video. I'd not seen this where the module shut down a circuit due to overcurrent and no fuse. Thanks!! (I was hoping you'd show what Mrs. O was cooking up for lunch, though! It's always nice to say Hello to Mrs. O.)
Whenever you don't see a circuit fused and the power source comes from a module the module will sense the amperage pull on the circuit and discount itself should the amperage draw exceed a predetermined level. Otherwise, the module becomes a very expensive fuse. When this occurs it is possible it will also set U codes. Great job as usual.
Timely video, I just bought me a Chevy Equinox yesterday. It doesn't have a the backup camera option though. My has the big old 3.4. I will have to get a spare set of heads and gaskets to keep on the shelf.
Maybe just buy spare car to keep on hand as a back up. I tell all Chevy owners to buy an extra pair of shoes because they will be walking soon be it fuel pump, head gasket, timing chain or whatever.....
Backup camera stopped working in my 13 Equinox. Didn't notice if it was causing a problem with the backup lights. Replaced the camera with OEM GM. As I recall, it had an updated part #. The new camera assembly looked higher quality, and gave a much clearer rearview than the original.
Another awesome video I like watching your videos mostly to help me rationalize that most repairs are rather simple and you know how to break the diagnosis down to simple terms...hey tell Mrs.O to make some soup!! LoL
I fuss about alot of things but, after watching your videos I'll never fuss about working on a vehicle from the south west. My vehicles look brand new compared to what you see.
Good job with literally smelling out the problem. You can have shorted bulbs too. Sounds really strange, but I have found it a couple of times where the wire in the bulb base breaks and shorts the bulb out internally.
It takes skill to have luck! You found those green crusties because you were bright enough to look. I suppose I might have found it by checking circuit resistance from the connector at the BCM, or maybe current when powered independently. It's a little disappointing they use the BCM to electronically bypass the circuit without setting a code to guide investigation. Old time fuse checking for each circuit was too easy.
The feature the power supply circuit in the BCM has for over-current protection is called "crowbar" if it's active circuitry. But it is more likely just a solid state fuse or a "polyswitch" in series with the output. Once it's tripped it needs to have power removed to reset.
Thanks for the video. I just sorted out some plug corrosion myself in this area. My backup camera and 3rd brake light was not working. Pulled everything apart like you did in the video and found some corrosion in the camera plug. I didn't have any deoxit so I used WD-40.
The good point of doing this at module level is that module can diagnose shorts or even open circuits since it is measuring the current and it most correlate to the action. If you put reverse and current peaks, it is a short, if it cant measure a value, its open and if you get current while reverse is not shifted, you got some short to another wiring. The bad news is short circuit protection implemented that way is not as fast as a fuse and you can risk the module or wiring, ok, small chances, still there.
Good video Eric. Good info on the BCM and the lighting system. I backup the old fashion way by turning my head and using my eyes. Guess you could say I'm ancient but it still works and has no shorts or burned out bulbs or odors . LOL 👍
Good video! An aftermarket camera would be relatively inexpensive to install if the customer needs one. I see Rockauto lists a camera, but they are currently out of stock.
If they design the outputs like what I'm currently doing for industrial applications (not necessarily the case; $0.1 more expensive per output, and they like selling modules apparently), you need a reasonable current probe to catch it: When gross overcurrent occurs, the output FET is turned off in 2-50 microseconds. The FET will reliably survive driving a dead short for 100 microseconds, during which time about 1kW is dissipated in the transistor. It is always a fun test to perform.
I worked on a 2007 or 2008 Ford Escape not too long ago. It had been in a collision and the body shop could not get the turn signals to work after doing repairing the damage to the front clip. Electrically, turn signals checked out fine - but it was not getting a signal out of the BCM/SJB. I plugged my scan tool into it and found that it had codes for shorted out turn signal circuits. Since I disconnected at the SJB and successfully powered up the lights with the power probe, I knew there wasn't a short. But unlike this GM product, the Ford BCM would not reset by cycling the ignition (or unplugging the battery). It required the codes to be cleared out of the BCM with my scan tool before it would attempt to power up that circuit again. All in all, it took 15-20 minutes to ship the car out the door...but kinda bothers me that you'd need a higher end scan tool to do this work (most DIY-level OBD2 scan tools I've seen won't access the BCM on these vehicles). It's one rare case where I prefer GM's implementation ('resetting' with the ignition switch rather than with a scan tool).
AKJeeper im assuming the Chevy in this case runs a self test of that circuit at every key cycle. With the camera plugged in it detected a malfunction at each key cycle and disabling power to lights im assuming. Sort of a modern day “fuse” circuit protection from a short taking out the BCM.
@@heyitschinoable I'm sure that's what it's doing. I prefer how GM appears to run a self-test, as opposed to the Ford I worked on where the code needed to be cleared with a higher-level scan tool before the circuit would power up again. Funny thing, is the Ford also had fuses for the circuit (which were blown, then replaced by the body shop...still no lights so that's how I ended up with it), so there's some redundancy there.
AKJeeper I would believe the fuses are there to protect the wiring or load(s). Although that does seem redundant. I worked on a Mustang EcoBoost once and the left front fog light would not work until the code was erased as well. Sort of weird.
Hey, what happened to the Mrs O cooking cameo? It's the best part of the video. She wears some snazzy outfits too. Like seeing Miss T too. She's probably at school though.
I said to myself don't trust the diagram not 2 seconds later you said the same thing....great minds think alike...lol. Nice approach as always. Thanks.
Smashing job, back in service in no time :-D. I would be supprised if the owner cares about a crappy camera. i expected there to be bare touching wires in the rubber gator across the hatch hinges. I've seen that in uk hatchbacks, and door to body wires typical.
Great video as always. Wish my repair was that easy. Waiting on GM to ship me a new alternator as the aftermarket ones are not strong enough on my high end Buick.
I just filmed a similar problem a week ago, except it was the compass display in the mirror and the back up lights didn't work. I found two separate issues on one (related) circuit. It was fun to diagnose. As I mentioned before, I appreciate the thought process and descriptions of the circuits here.
I wasnt going to watch this but I am glad I did. Very interesting. Good work! Damn Cameras! LOL!! Would love to hear if the owner wanted it fixed or not.. If it were mine, I would have searched for a good used part.
Based on what I’ve noticed with the rust and moisture issues you encounter in the Northeast and owners who are not willing to invest too much in replacement parts, I assume that most of these vehicles seem to meet the crusher at 12 to 13 years old.
I was surprised a fuse didn't blow when you plugged the camera back in and I saw the back up light flash for a moment and knowing you smelled the camera burning. Seems like a good cause for a possible fire. Thanks for sharing. Might be able to use a 'generic' camera.
Nicely done Eric! I can back up like a boss but I do miss my camera when I'm in cars without one. Plus I hate when something is broken even if I don't use it. I'd replace it 🙈😂😂
I think that using a "module" to provide power to 3 different loads is over-complicating things. Each load could have easily had its own fuse, making t-shooting easy as pie. Meanwhile, back in the shop, Eric does his usual efficient work and finds the problem. Thanks for the revelation.
Had no backup lights on an 04 express 3500 van. Was thinking bad range switch because the fuse was good. Good thing I checked the wiring diagram. BU LAMP fuse was for the backup light circuit in the trailer wiring, not the backup lights! Backup lights on the van are powered by the BCM. Replaced a blown BCM fuse and fixed backup lights and the dome lights. Got a two-fer on that one.
Current sense resistor / current shunt. It is a low value resistor, like 0.01 ohms, and basically a 'voltmeter' across it. The ohms law say: V = A * R, so the voltage read equal to the amperage multiplicated by the resistance. In other words, a 0.01 ohms give 0.01V per amps passing throught it. Want a 10A limit? Have a sense that trip at 0.1V. It is usually done with some opamp, a dual opamp setup can do the trick. The first one is in differential mode, and the two inputs goes across the resistor. It will simply amplify the voltage across the resistor to a more usable one. The second opamp is used as a comparator. One input is fed from a reference (ex 5V, possibly via a voltage divider resistor network (really, it's 2 resistors) to drop it to like 2.5V or whatever), the second input goes to the output of the first. What it do is amplify the difference between the reference and the signal. Since there is no feedback to adjust the gain, the gain is basically over a million! So what really happend is that the output will be low or high. Let's say 10A limit, 0.01ohms, gain of 10, vref 1V.... 10.1A into the resistor give V=A*R = 10.1A*0.01R = 0.101V signal. Differential amp with 10x gain, output is now 1.01V. Second opamp amplify the difference between 1V and 1.01V, difference is 0.01V, multiplied by the open loop gain of over a million. It can't output more than it's power supply, let's say 5V, so it will output 5V. If you have 9.9A, the output would be: 0.099V, gain of 10: 0.99V, differential to 1V ref: -0.01V, gain of over a million would be bellow the negative supply, which is 0V, can't go over the supply, will output 0. Now, feed that signal to the BCM and voila! you have a current limiter. Take note that this is slightly simplified, one issue is that a lightbulb use more power when cold than when hot. So a delay is needed. It can be done in software (if the overcurrent is tripped for more than 0.1 second?) or a low pass filter can be added to the opamp setup to slow down the response time. In reality, probably both are used: a fast low pass to filter the interferences (because a car have a shitton of noise. Want to design a stable circuit? design it for a car environnement. If you succede it will basically be bullet proof when on a powersupply or battery), then use a shorter time software delay... Edit: As for FET/MOSFET... it is like a normal transistor, but work differently. A normal transistor, which is called a BJT (bi-junction transistor) is a current amplifier. The 'control' current is amplified by the transistor gain, and that is what current can flow. Main disadvantage: it have around 0.6-1V of loss. At 10A that is 6-10W of heat ! And a power transistor have a low gain. For the 10A you may need to feed 0.1A to it's base (control input), which is too much for a microcontroller, so you need yet another transistor to amplify the microcontroller current and proprelly feed the power transistor. A MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is voltage controlled. The voltage at the gate (control input) control how much the 'valve' open. Main advantage is that it do not have a 'fixed' voltage drop like BJT does, but have a resistance instead. A good N-Chan fet can be bellow 0.01 ohms. At 10A that would drop 0.1V and be only 1W. You can parallel more than one to drop the voltage drop and resistance, ex: 2 would be 0.05V and 0.5W at 10A. Main disadvantage is that p-chan fet are not great. A P-Chan would sit on the positive supply (12v) and would be turned on by putting the gate low (ex: 0V). You can however use a N-Chan, but in this case you need to raise the gate voltage above the supply (ex: 12V + 10V = 22V, when the engine is running that is 14.4+10V = 24.4V). There is some specialised chip for this that take care of everything so it is not a big issue, but make the circuit more complex. This is why most of the control now switch the negative side. The N-Chan fet can sit on the ground side, and the gate can be turned to 0+10V = 10V, which is bellow the battery voltage, so no special circuit is needed! In fact, you have some 3.3V microcontroller compatible mosfet, so you don't need +10V but +3.3V, since it is referenced to ground (0v) that is ideal for a direct to microcontroller connection! All you need is a simple resistor for a low frequency signal!
People fit their own cameras to rear lights (takes about 1Amp) and the tail/reverse lights won't function right. Its because in modern cars, the BCM supplies and monitors the bulbs, this allows protection as Eric said, but also allows for system to announciate a faulty bulb! The moral is don''t connect power feed for aftermarket camera to light circuits!
tomctutor you’d need to tap the reverse light circuit to power a relay (solid state or otherwise) to then turn on power from a separate power feed from +12V.
Nice diagnosis & $174 & just had to buy one for my wife's Traverse about a month ago...exact same problem only her license plate lights were good. I had to fix hers b/c she said needs it so it's fixed :D
GM is great at introducing "new" technology aren't they I remember when they went to EFI the failure rate on Mass air flow sensors was close to 100%..BTW Better start pricing timing chains for that V-6 the GM timing chains now look like a two link bicycle chain vs a multi link design used by pretty much the rest of the industry.
@@robc8468 They'll be fine. Every manufacturer has had or still has engine issues, fires from fuel/oil leaks or electronic devices burning down homes, air bags, transmissions going to low at highway speeds & the list goes on & on. I fix them all!
Theres probably a hall effect device built into the driver chip in the Bcm, it detects overcurrent. A chip will most likely have the Fet and current semsor built in. Hall effect current sensors pick up the magnetic field around the wire or pcb trace, pretty much like a current clamp. Current sense resistors are old fashioned now.
Just looked it up...a new, oem back up camera for the Equinox is $107 from GM Parts Warehouse....i would have you replace it for that much money if it were my car...
I was thinking the same thing, but I was too lazy to look it up.... But yeah, I think you can just order the little camera. $107?? I'd do that. I love my backup camera....
@@ericcorse We call that the braille method of parking. Back up until you bump the car behind you, pull forward until you bump the car in front of you.
More dumbing down with a rear view camera my old fashioned mirrors never let me down😊 how many times I have to watch cars at ten at night with no headlights because they assuming that they automatically were on when car was on!
just had this with a Jeep; everything but the defroster was out. also happened on a Mitsubishi rear wiper motor, which also seemed to affect the plunger release for the hatch lock. both vehicles had bigger problems than that, though.
pretty sure it's supposed to be a "smart" device and tell if there's an bulb out or overload issue and there's probably multiple fuses feeding it. Now if there's a major short and BCM failure both, then it relies on the upstream feeder fuse to blow, I'd imagine there's be some crispy burnt scent and smoke wafting about from the BCM by then lol
@@throttlebottle5906 Unfortunately, no fuse is faster at blowing than semiconductor switches downstream (FETs, transistors, etc) so they end up being only good to protect wiring. No one wants to replace a module just because of a shorted wire. They have some pretty awesome devices nowadays that can detect & shutdown short currents, load dumps, overheating, just about whatever you can throw at them and rat on you back to the computer. Infineon BTS50055-1TMC for example. Though I agree; all this complication is just so GM can turn on the reverse lights for a while after you park. But all those stupid features apparently sell vehicles.
Paul Moir your comment helped me a lot. Today for example i had an issue with ambient air temp reading -22F. Compressor would not kick on as BCM was interpreting it as freezing cold when it was actually 60F. That 5V ref for the temp sensor is not fuse protected either. So the BCM might have a circuit sense to it possibly.
I was just in Harbor Freight and was going to buy some 3/8 impacts and a ball joint kit. My wife turned to me and said "Hey doesn't Eric o have these in his Amazon store?" I said ya but a lot more expensive. She replied "well I rather you buy it from his store and besides it's probably more money because its a lot better stuff." she pulls out her phone and says "Ya see right here he has them in his store." I'm thinking 'she has Eric O's Amazon store saved on her phone?' :)
If in your next video you can smell what cilinder is misfiring by sticking your nose in the exhaust i'm even more impressed!😜
sniffing exhaust is a must, just not too much lol
did i tell you about the gifted mechanic? he did a valve job through the tailpipe. rhumor has it he was a proctologist at night
Is that sort of like the old Redd Fox story about the woman smelling the ducks asses in the Supermarket to tell where they are from---when she asks Redd where he is from--he bends over and say's to her "you tell me". LOL
@@KStewart-th4sk 🤣🤣
Dan is revealing his own super powers by asking others if, by chance, they have the same power as he. Nice! I'm on to you bud!
Finally someone on TH-cam from New York State, and not Florida or the West coast! Wish I can bring my car over there, a good mechanic who is honest is a dime a dozen and here in buffalo there even rarer
I have worked in the high tech world of computers for 20+ years and your logic and methodology of diagnosing the issue was the same we use to resolve similar issues. Great Video.
Hey I just grabbed one of your videos to say you are awesome! 65 an hour you are dirt cheap and one of the best in diagnostics I have seen. Short of my hs shop teacher!! lol Thanks so much for everything you do and for putting it out for the world to see!
I gotta tell ya i love this channel it is simply entertaining and very informative ...and it shows what a “Real Mechanic” should be ..highly trained and exceptional at his craft...thank you for the video...
Nothing better than watching Dr. O in action...masterful
I love the sound of the noon whistle. My little town blew the fire whistle at noon and two surrounding towns blew theirs at 6 PM.
BTW, I tuned in hoping for another brake job video. I actually like watching them and the parts changing videos.
Hey Eric - another great video. Also wanted to say I’m new to your channel and I’m hooked. I’ve been binge watching your old stuff nonstop for the past week. Absolutely love watching- you’re so thorough and I always learn something. You also have a wonderful family, and I find your “distractions” entertaining and usually really funny. Love the “toots” and “boogerd threads”. You’ve got the most informative and also entertaining automotive repair videos out there (I still feel this way even though I own two Audi’s and a VW - I know you hate working on them!). Sorry for the long post, but I just had to share my appreciation!
Thanx Eric. You seem like a very knowledgeable and cool guy.
These are the kind of videos that made SMA famous! Real life issues that most shops would have replaced the BCM. Great video.
What's bcm
@@joshbgo3676 Body Control Module
The Best time at South Main Auto is Lunch....Thank You Mrs. O for feeding Eric O....
Thank you for opening a tool website. I am always adding/replacing tools
and I will definitely be buying from it to show my gratitude and
support for the outstanding videos you produce. I am happy I found your
videos.
Great video. That was an awesome diagnosis and quick repair. Those cameras are a pain and I seriously doubt if a junkyard has a good one. They seem to have a life expectancy of about five years. Thanks for the video!
Diag-nose-tics! Thanks for another great vid, Eric.
I use a flat screwdriver and a cloth to remove the taillight. I put it in the gap in between the plastic lens and quarter panel and wiggle it back and forth. No chance of damaging it from yanking it off. Works great for the stubborn ones.
i went to check the price for that rear trim with the camera.... MAN $300 bucks for it! OUCH at that point yes i can definitely live without a camera, great video again Eric! cheers!
You are right about the bulbs. In the mid 80s, I think 85, on New Year's night, after ringing in the new year, I got in the car, started it, turned on the headlights, and both flashed and went out. Clicked high beams, had them. Low beam, dead. What can it be? Bad switch? Bad relay? Ground? I thought surely it can't be, but I went the next day and bought 2 new sealed beam headlamps to replace the aftermarket halogen ones I had installed a little over a year earlier. Had low beams again. Check the bulbs first.
Thank you, thank you, thank you. I run into this kind of stuff quite often while doing used car safety checks. I try to explain to my boss that spending some time and pinpointing the actual issue is much more cost effective then shooting the parts cannon and hoping for a hit. ( some guys just don't get it). I have found that with some vehicles you can graft in an aftermarket back up cam and get it to work with the stock system (not my preference but it can work) at a much lower cost then the factory cam. But this video (going to make my boss watch) will save my bacon from yet another heated discussion with the boss man. Thanks my friend and keep up the great work. L&R to you and the crew at SMA....
Diagnosing a problem can take a lot of patience and a lot of time. Some guys just don't wanna wait that long before they start turning screws and swapping pieces.
Guys like that could care less about what it is costing the customer. The more parts they can sell, whether actually needed, they could care less.
Your my favorite mechanic, I like how you logic, and your bedside manner is tops auto Doc!
Oh crap, now I have to watch to the end to find out what this issue is. That burnt up electrical smell is unique and it does work to diagnose electrical components. I've done the same thing many times.
I was able to do the same to my vehicle after seeing this video. I wasn’t sure about taking the panel off, but I did it. Now my back up lights and license plate lights work . Thank you
The field-effect transistor is an electronic device which uses an electric field to control the flow of current. FETs are 3-terminalled devices, having a source, gate, and drain terminal.Wikipedia
Another great video. I too was confused no seeing a fused circuit lately. No I know the module can control the current. Thanks for making this
Always a great informative video. I’ve learned to always start with the easy stuff. Many times I’ve forgot and went off what a customer said instead of being smart.
Thanks for the analysis. I really enjoyed the technical aspects. No reverse lights and no backup camera because the camera burnt out.
Another great video. On plastic trim tabs I put a little Vaseline on them and really helps going back together as well as coming apart a next time.
Jiggle the wiper arms.
It's not a Chrysler, so that won't work.
I don't even have a Chevy Equinox but I still found this informative.
Eric i admire how you do a thorough trouble shooting
"Follow your nose!"
Dan'sMeTube nose knows
A fix on a modern car with no scan tool needed?! NOWAY!
You should be a game show host, so when you announce what the prizes will be, "Top prize is a 2019 CHHHHHH-EVRO-LEEEEEEET!"
As a computer tech for 15 years, it tickles me to see someone else use T-pins as tools. I used them far more times to probe or pick things apart then I ever did to put things on my cube wall. They are phenomenal as tools!
Boy!!! Do you ever make it look easy to find the problem in the electrical system. But hey, when you been doing for so long, you get to the point that you know what your looking for. Nice video, Eric....
Old school small town whistle..... like the flintstones. Nice video fred!
Seriously, though, great video. I'd not seen this where the module shut down a circuit due to overcurrent and no fuse. Thanks!! (I was hoping you'd show what Mrs. O was cooking up for lunch, though! It's always nice to say Hello to Mrs. O.)
I'll bet Dorman has parts ready for you🤣
probably is Dorman, sold under different label.........
I’m pretty sure GM uses dorman for its main supplier anyway...
@ hahaha
Dorman 590-068?
the dorman part image will be upside down and reversed
Whenever you don't see a circuit fused and the power source comes from a module the module will sense the amperage pull on the circuit and discount itself should the amperage draw exceed a predetermined level. Otherwise, the module becomes a very expensive fuse. When this occurs it is possible it will also set U codes. Great job as usual.
Timely video, I just bought me a Chevy Equinox yesterday. It doesn't have a the backup camera option though. My has the big old 3.4. I will have to get a spare set of heads and gaskets to keep on the shelf.
Maybe just buy spare car to keep on hand as a back up. I tell all Chevy owners to buy an extra pair of shoes because they will be walking soon be it fuel pump, head gasket, timing chain or whatever.....
@@robc8468 I have spare cars.
your videos helped me on plenty of jobs !!!! thanks man
Backup camera stopped working in my 13 Equinox. Didn't notice if it was causing a problem with the backup lights. Replaced the camera with OEM GM. As I recall, it had an updated part #. The new camera assembly looked higher quality, and gave a much clearer rearview than the original.
Eric you have a great channel. I have been watching since you went to the Eric the car guy meet up. That's how I learned about your channel.
mobes329 Eric the car guy is a douche!🐊
Awesome diagnosis and repair Eric. Thank you for bringing us along.👍👍
Another awesome video I like watching your videos mostly to help me rationalize that most repairs are rather simple and you know how to break the diagnosis down to simple terms...hey tell Mrs.O to make some soup!! LoL
I fuss about alot of things but, after watching your videos I'll never fuss about working on a vehicle from the south west. My vehicles look brand new compared to what you see.
Eric O, another great video! I catch myself saying Chevrolet the same way now! Happy 2020 everyone!
Good diagnosis I like the way you break it into smaller pieces ,that makes it Easier to understand
Good job with literally smelling out the problem.
You can have shorted bulbs too. Sounds really strange, but I have found it a couple of times where the wire in the bulb base breaks and shorts the bulb out internally.
It takes skill to have luck! You found those green crusties because you were bright enough to look. I suppose I might have found it by checking circuit resistance from the connector at the BCM, or maybe current when powered independently. It's a little disappointing they use the BCM to electronically bypass the circuit without setting a code to guide investigation. Old time fuse checking for each circuit was too easy.
The feature the power supply circuit in the BCM has for over-current protection is called "crowbar" if it's active circuitry. But it is more likely just a solid state fuse or a "polyswitch" in series with the output. Once it's tripped it needs to have power removed to reset.
This is close to what I needed Thank You!
Thanks for the video. I just sorted out some plug corrosion myself in this area. My backup camera and 3rd brake light was not working. Pulled everything apart like you did in the video and found some corrosion in the camera plug. I didn't have any deoxit so I used WD-40.
The good point of doing this at module level is that module can diagnose shorts or even open circuits since it is measuring the current and it most correlate to the action. If you put reverse and current peaks, it is a short, if it cant measure a value, its open and if you get current while reverse is not shifted, you got some short to another wiring. The bad news is short circuit protection implemented that way is not as fast as a fuse and you can risk the module or wiring, ok, small chances, still there.
If it's a Smell-O-Vision camera, it's working as intended.
Sorry I haven’t committed for awhile but still watching the videos and liking them keep up the great work thanks for the content
Good video Eric. Good info on the BCM and the lighting system. I backup the old fashion way by turning my head and using my eyes. Guess you could say I'm ancient but it still works and has no shorts or burned out bulbs or odors . LOL 👍
😂😂👍🏻👏🏻👏🏻
You can also use your key fob transmitter hitting unlock will turn on backup lamps for perimeter lighting for few seconds on most.
Good video! An aftermarket camera would be relatively inexpensive to install if the customer needs one. I see Rockauto lists a camera, but they are currently out of stock.
If they design the outputs like what I'm currently doing for industrial applications (not necessarily the case; $0.1 more expensive per output, and they like selling modules apparently), you need a reasonable current probe to catch it: When gross overcurrent occurs, the output FET is turned off in 2-50 microseconds. The FET will reliably survive driving a dead short for 100 microseconds, during which time about 1kW is dissipated in the transistor. It is always a fun test to perform.
Thought the outside of that plug looked scorched it did from here anyways
Yeah, that's what I thought, unless it was rust stains masquerading as burn marks.
It might be old dielectric grease
I worked on a 2007 or 2008 Ford Escape not too long ago. It had been in a collision and the body shop could not get the turn signals to work after doing repairing the damage to the front clip. Electrically, turn signals checked out fine - but it was not getting a signal out of the BCM/SJB. I plugged my scan tool into it and found that it had codes for shorted out turn signal circuits. Since I disconnected at the SJB and successfully powered up the lights with the power probe, I knew there wasn't a short. But unlike this GM product, the Ford BCM would not reset by cycling the ignition (or unplugging the battery). It required the codes to be cleared out of the BCM with my scan tool before it would attempt to power up that circuit again. All in all, it took 15-20 minutes to ship the car out the door...but kinda bothers me that you'd need a higher end scan tool to do this work (most DIY-level OBD2 scan tools I've seen won't access the BCM on these vehicles). It's one rare case where I prefer GM's implementation ('resetting' with the ignition switch rather than with a scan tool).
AKJeeper im assuming the Chevy in this case runs a self test of that circuit at every key cycle. With the camera plugged in it detected a malfunction at each key cycle and disabling power to lights im assuming. Sort of a modern day “fuse” circuit protection from a short taking out the BCM.
@@heyitschinoable I'm sure that's what it's doing. I prefer how GM appears to run a self-test, as opposed to the Ford I worked on where the code needed to be cleared with a higher-level scan tool before the circuit would power up again. Funny thing, is the Ford also had fuses for the circuit (which were blown, then replaced by the body shop...still no lights so that's how I ended up with it), so there's some redundancy there.
AKJeeper I would believe the fuses are there to protect the wiring or load(s). Although that does seem redundant. I worked on a Mustang EcoBoost once and the left front fog light would not work until the code was erased as well. Sort of weird.
Hey, what happened to the Mrs O cooking cameo? It's the best part of the video. She wears some snazzy outfits too. Like seeing Miss T too. She's probably at school though.
I said to myself don't trust the diagram not 2 seconds later you said the same thing....great minds think alike...lol.
Nice approach as always. Thanks.
Sounds like the big 2.4 is ready for a timing set!
Well done sir. Love these type of diagnosing you do.
Smashing job, back in service in no time :-D.
I would be supprised if the owner cares about a crappy camera.
i expected there to be bare touching wires in the rubber gator across the hatch hinges.
I've seen that in uk hatchbacks, and door to body wires typical.
Great video as always. Wish my repair was that easy. Waiting on GM to ship me a new alternator as the aftermarket ones are not strong enough on my high end Buick.
I just filmed a similar problem a week ago, except it was the compass display in the mirror and the back up lights didn't work. I found two separate issues on one (related) circuit. It was fun to diagnose. As I mentioned before, I appreciate the thought process and descriptions of the circuits here.
I wasnt going to watch this but I am glad I did. Very interesting. Good work! Damn Cameras! LOL!! Would love to hear if the owner wanted it fixed or not.. If it were mine, I would have searched for a good used part.
Based on what I’ve noticed with the rust and moisture issues you encounter in the Northeast and owners who are not willing to invest too much in replacement parts, I assume that most of these vehicles seem to meet the crusher at 12 to 13 years old.
Like the addition of the SOUTHMAINAUTO plate.
"Was it over when the germans bombed Pearl Harbor?"
Eric,
Great video and diagnosis - thank you!
SMA#1
God bless
Paul
I was surprised a fuse didn't blow when you plugged the camera back in and I saw the back up light flash for a moment and knowing you smelled the camera burning. Seems like a good cause for a possible fire. Thanks for sharing. Might be able to use a 'generic' camera.
Great fix Eric O 👍🏻 Stevie 🇬🇧
Great video Dr O, nice bit of hard wire work.
Thanks for sharing and best regards from the UK.
Always learning thxs Eric,what no tour of the SMA on what Mrs O is cooking up for lunch...
Ok...I literally laughed out loud when you said "RUN!!" when the lunch horn went off.
Nicely done Eric! I can back up like a boss but I do miss my camera when I'm in cars without one. Plus I hate when something is broken even if I don't use it. I'd replace it 🙈😂😂
GM: "Quit nosing around!" Eric: "Nope".
I think that using a "module" to provide power to 3 different loads is over-complicating things. Each load could have easily had its own fuse, making t-shooting easy as pie. Meanwhile, back in the shop, Eric does his usual efficient work and finds the problem. Thanks for the revelation.
Had no backup lights on an 04 express 3500 van. Was thinking bad range switch because the fuse was good. Good thing I checked the wiring diagram. BU LAMP fuse was for the backup light circuit in the trailer wiring, not the backup lights! Backup lights on the van are powered by the BCM. Replaced a blown BCM fuse and fixed backup lights and the dome lights. Got a two-fer on that one.
SMA "smell the camera" , Spinal Tap "smell the glove", Me " I smell a Good video", Thanks Eric
Current sense resistor / current shunt.
It is a low value resistor, like 0.01 ohms, and basically a 'voltmeter' across it. The ohms law say: V = A * R, so the voltage read equal to the amperage multiplicated by the resistance. In other words, a 0.01 ohms give 0.01V per amps passing throught it. Want a 10A limit? Have a sense that trip at 0.1V.
It is usually done with some opamp, a dual opamp setup can do the trick. The first one is in differential mode, and the two inputs goes across the resistor. It will simply amplify the voltage across the resistor to a more usable one. The second opamp is used as a comparator. One input is fed from a reference (ex 5V, possibly via a voltage divider resistor network (really, it's 2 resistors) to drop it to like 2.5V or whatever), the second input goes to the output of the first. What it do is amplify the difference between the reference and the signal. Since there is no feedback to adjust the gain, the gain is basically over a million! So what really happend is that the output will be low or high.
Let's say 10A limit, 0.01ohms, gain of 10, vref 1V.... 10.1A into the resistor give V=A*R = 10.1A*0.01R = 0.101V signal. Differential amp with 10x gain, output is now 1.01V. Second opamp amplify the difference between 1V and 1.01V, difference is 0.01V, multiplied by the open loop gain of over a million. It can't output more than it's power supply, let's say 5V, so it will output 5V.
If you have 9.9A, the output would be: 0.099V, gain of 10: 0.99V, differential to 1V ref: -0.01V, gain of over a million would be bellow the negative supply, which is 0V, can't go over the supply, will output 0.
Now, feed that signal to the BCM and voila! you have a current limiter.
Take note that this is slightly simplified, one issue is that a lightbulb use more power when cold than when hot. So a delay is needed. It can be done in software (if the overcurrent is tripped for more than 0.1 second?) or a low pass filter can be added to the opamp setup to slow down the response time. In reality, probably both are used: a fast low pass to filter the interferences (because a car have a shitton of noise. Want to design a stable circuit? design it for a car environnement. If you succede it will basically be bullet proof when on a powersupply or battery), then use a shorter time software delay...
Edit:
As for FET/MOSFET... it is like a normal transistor, but work differently. A normal transistor, which is called a BJT (bi-junction transistor) is a current amplifier. The 'control' current is amplified by the transistor gain, and that is what current can flow. Main disadvantage: it have around 0.6-1V of loss. At 10A that is 6-10W of heat ! And a power transistor have a low gain. For the 10A you may need to feed 0.1A to it's base (control input), which is too much for a microcontroller, so you need yet another transistor to amplify the microcontroller current and proprelly feed the power transistor.
A MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is voltage controlled. The voltage at the gate (control input) control how much the 'valve' open. Main advantage is that it do not have a 'fixed' voltage drop like BJT does, but have a resistance instead. A good N-Chan fet can be bellow 0.01 ohms. At 10A that would drop 0.1V and be only 1W. You can parallel more than one to drop the voltage drop and resistance, ex: 2 would be 0.05V and 0.5W at 10A. Main disadvantage is that p-chan fet are not great. A P-Chan would sit on the positive supply (12v) and would be turned on by putting the gate low (ex: 0V). You can however use a N-Chan, but in this case you need to raise the gate voltage above the supply (ex: 12V + 10V = 22V, when the engine is running that is 14.4+10V = 24.4V). There is some specialised chip for this that take care of everything so it is not a big issue, but make the circuit more complex. This is why most of the control now switch the negative side. The N-Chan fet can sit on the ground side, and the gate can be turned to 0+10V = 10V, which is bellow the battery voltage, so no special circuit is needed! In fact, you have some 3.3V microcontroller compatible mosfet, so you don't need +10V but +3.3V, since it is referenced to ground (0v) that is ideal for a direct to microcontroller connection! All you need is a simple resistor for a low frequency signal!
Here it is Satuday and I figured we'd be seeing another weekend Chrysler electrical adventure.
Nope...we got us a Shivvy.
Not another brake job? :(
Shivvy is best we got
People fit their own cameras to rear lights (takes about 1Amp) and the tail/reverse lights won't function right. Its because in modern cars, the BCM supplies and monitors the bulbs, this allows protection as Eric said, but also allows for system to announciate a faulty bulb!
The moral is don''t connect power feed for aftermarket camera to light circuits!
tomctutor you’d need to tap the reverse light circuit to power a relay (solid state or otherwise) to then turn on power from a separate power feed from +12V.
Nice diagnosis & $174 & just had to buy one for my wife's Traverse about a month ago...exact same problem only her license plate lights were good. I had to fix hers b/c she said needs it so it's fixed :D
GM is great at introducing "new" technology aren't they I remember when they went to EFI the failure rate on Mass air flow sensors was close to 100%..BTW Better start pricing timing chains for that V-6 the GM timing chains now look like a two link bicycle chain vs a multi link design used by pretty much the rest of the industry.
@@robc8468 They'll be fine. Every manufacturer has had or still has engine issues, fires from fuel/oil leaks or electronic devices burning down homes, air bags, transmissions going to low at highway speeds & the list goes on & on. I fix them all!
Thank you Mr ‘O’, great video.
waffles with REAL MAPLE syrup and SMA videos,aaahhh life is great!
sterling stephens
Theres probably a hall effect device built into the driver chip in the Bcm, it detects overcurrent.
A chip will most likely have the Fet and current semsor built in.
Hall effect current sensors pick up the magnetic field around the wire or pcb trace, pretty much like a current clamp.
Current sense resistors are old fashioned now.
Just looked it up...a new, oem back up camera for the Equinox is $107 from GM Parts Warehouse....i would have you replace it for that much money if it were my car...
The car is probably worth $250!
That seems reasonable enough! Only $107???
I was thinking the same thing, but I was too lazy to look it up.... But yeah, I think you can just order the little camera. $107?? I'd do that. I love my backup camera....
@@janpur1417 Car is worth $4000 in the condition it is in...
won't be long before it needs head gaskets anyhow :/
You don't have to remove the trim to change plate lights, you can pop out the assembly with a small screwdriver
Nice methodical troubleshooting 👍
I like the SMA license plate covers!
Ya' don't need no stinkin' camera anyway! Thanks Dr. O!
Back up till you hear glass breakin.
@@ericcorse We call that the braille method of parking. Back up until you bump the car behind you, pull forward until you bump the car in front of you.
I am surprised the module allowed the car to run without a camera plugged it.
@@robc8468 Why ?
More dumbing down with a rear view camera my old fashioned mirrors never let me down😊 how many times I have to watch cars at ten at night with no headlights because they assuming that they automatically were on when car was on!
just had this with a Jeep; everything but the defroster was out. also happened on a Mitsubishi rear wiper motor, which also seemed to affect the plunger release for the hatch lock. both vehicles had bigger problems than that, though.
pretty sure it's supposed to be a "smart" device and tell if there's an bulb out or overload issue and there's probably multiple fuses feeding it.
Now if there's a major short and BCM failure both, then it relies on the upstream feeder fuse to blow, I'd imagine there's be some crispy burnt scent and smoke wafting about from the BCM by then lol
Ah curry and an SMA video, good Saturday night in!
Mrs O's famous line 'If he can do it, you should give it a try' still makes me laff that does. 😂
they engineered current sense circuits to save the modules and to report trouble codes for shorts high, low or open
fuse, the original easy to repair current sense circuit device ;))
cost a buck per car.......bean counters noway
@@throttlebottle5906 Unfortunately, no fuse is faster at blowing than semiconductor switches downstream (FETs, transistors, etc) so they end up being only good to protect wiring. No one wants to replace a module just because of a shorted wire. They have some pretty awesome devices nowadays that can detect & shutdown short currents, load dumps, overheating, just about whatever you can throw at them and rat on you back to the computer. Infineon BTS50055-1TMC for example. Though I agree; all this complication is just so GM can turn on the reverse lights for a while after you park. But all those stupid features apparently sell vehicles.
Amundsen great explanation thanks! Im assuming if there was a short and had a high amperage draw it would possibly take out the module correct?
Paul Moir your comment helped me a lot. Today for example i had an issue with ambient air temp reading -22F. Compressor would not kick on as BCM was interpreting it as freezing cold when it was actually 60F. That 5V ref for the temp sensor is not fuse protected either. So the BCM might have a circuit sense to it possibly.
I was just in Harbor Freight and was going to buy some 3/8 impacts and a ball joint kit. My wife turned to me and said "Hey doesn't Eric o have these in his Amazon store?" I said ya but a lot more expensive. She replied "well I rather you buy it from his store and besides it's probably more money because its a lot better stuff." she pulls out her phone and says "Ya see right here he has them in his store." I'm thinking 'she has Eric O's Amazon store saved on her phone?' :)
Dorman makes that camera separate if you were interested its part # 590-068 im a parts guy in mass. And ive sold a few of these