chinese started minimising wires, sizes, wire is measured as a square amount or round, not sure which, but the chinese make it the smaller.. so your wire gauge is wrong. now car manufactures do the same, everything minimal, so,,it dont last & it breaks..buy pre 90 cars,, built correct..even wall plugs, are now made of sht alloy,,not copper.. same as power trans lines, alloy, rubbish,,.
Eric O, get yourself and 2 ohm resistor when your jumping airbag connectors. We used to use those on a breadboard, to test wire harnesses in place of air bags and impact sensors. This allowed us to test harnesses without risking lighting off airbags, and it would fool the control module into thinking the module or sensor was present. We built protoype harnesses for OEM development, this is how we tested them before installing them into vehicles.
I like Eric's procedure removing the door panels. Aggression without Excessing. He respects the customers equipment, not breaking things. Common sense goes a long way in auto diagnostics.
We visit my wife’s family at the farm they own in Michigan. I never go in winter it’s to cold for me. Colorado is not nearly as cold. Also the roads in Michigan are pure ice. Stay warm brother.
Mr. O. is on hunt, yet again, to solve the elusive Envision sensor mystery. Will the new sensors fix the problem? Is Mr. O. on a wild goose chase? Will the lovely Mrs. O. grace us with an appearance? Can Mr. O. get the doors back together without the use of naughty words? Stay tuned for the next episode!
Some manufacturers do not allow srs wiring repairs if there is soldering or wire cutting involved. Toyota and Lexus are the most strict. You can look in their position statements to find out. Only legal option is to replace the harness in that case. Mopar sells repair kits for theirs and if you use anything other than that, if an accident happens and the system doesn't work coz you repaired the srs harness with something other than their kit your probably in hot water. Food for thought, working in the insurance repair industry the last few years has shown me a lot of technicalities i never thought of
Yeah we were never allowed to repair damaged SRS or airbag wiring in the body shops, which sucked, because it did hinder a lot of repairs that would have been economical. However legally we were not allowed. Wasn't worth the headache at our shop.
@dropinbiking92 I do it every day lol. I also replace a ton of harnesses with Asian manufacturers. Good money but terribly wasteful on their part. It comes down to resistance or probability of failure and someone suing the auto maker
GM actually had a recall on the R/V vans to remove a connector under both seats, and solder the wires to by-pass the connector. Then, they had a recall to inspect the previous techs work. It turned into a cluster f@ck. I found SRS wires simply twisted and taped!!!! Oh and if the next guy had to remove front seats, he would have to cut the wires. WTF GM!?!
Honda for example refer to SRS harnesses as having measured resistance, and so no alterations are allowed by splicing, soldering or cutting of any SRS wiring.Having all the connectors, loom or tape etc in yellow denotes them as specific to the SRS sustem. Also when you remove a connector it automatically shorts itself internally until the latch is retracted and it is reconnected to a sensor.
Hope the owner approves the repair and we get a part 2. Always love these electrical diag videos. Something I always want to improve myself with and you are helping me with your videos!!! Thank you for always making videos of cars that come into your shop!!! Hope all is well with you and also the family!!!! Love the channel!!!!
Always fascinating, Eric…your videos about diagnosing tough problems are case studies in logic just as much (or more) than mechanics. Thanks for the education!
Regarding the loose fit of the connector on the LF impact sensor, it might have been caused by someone attempting to read voltage at the connector with a DMM. I caused a similar problem with the ABS system on a truck I used to own by probing the connector. I had inadvertently widened the socket and caused an open circuit to be detected by the system. I had to use a dental pick to bend the socket back to its normal shape, which fixed the problem.
If you think about it, the reason for the sensors setting a code on the opposite side and the door behind it is simply to give the vehicle the ability to sense a side impact where one of the sensors is working at all times on one side of the vehicle. It is a way of producing redundancy in the system and saving lives because it you linked both sensors on the same side into a common circuit, if one quits you lose the second and thus allow that side of the vehicle to have no ablity to sense an impact.
@@LesReevesyou think or you don’t think 🤷🏻♂️ like gm has been for a decade now. If no one is sitting in passenger seat. That side of airbags are not activated 😉😉💁♂️😂
I work at a GM dealership body shop and my standard method for those door trim panels is once I get the panel off, the glass seal just slides off the metal clips then you can easily remove them individually and insert them back to the edge of the door and push the glass seal back onto them. Also a quick pass with a propane torch will bring the sticky back to that barrier adhesive.
@@pontiacsrule8761 it works great you just have to be careful, it’s a fine line between softening up the glue and melting the plastic, I usually make like three fairly quick passes and it evenly warms the glue without damaging anything.
GREAT video, as always. It makes sense if the sensors in opposite corners are related. If not physically, at some level within the SRS module. If a car is hit on a corner (hard enough for the airbag to deploy), the person sitting in the opposite corner will likely smack their head, if their airbag doesn't also deploy.
That makes no sense. If you are sitting on the left side of the car and someone is sitting on the right side of the and the car is hit from the right, the person on the right will have their head smashed into the side of the car as the car is pushed towards them. The person on the left is going to be pushed towards the center of the car as the car is being pushed away from them. So, no, the person on the opposite side of the car isn’t going to smack their head against the air bag on their side of the car.
@@LTVoyager When the car's movement stops, the person opposite from the impact actually could impact the door on their side as they will still have momentum. This is how whiplash occurs during a head-on or rear-end collision.
Using a DMM with the standard probe tips can certainly cause damage to the connectors especially when the contacts a smaller than the probe tips. When working on micro electronics in our meter shop, we had probe extensions that went over the standard DMM probe tips that reduce the tip of the probe by half the size. Eliminating connector damage by forcing/spreading the contacts apart.
Love them GM cars! 13 codes...My Dakota is 23 years old,no codes-go figger Built when Mercedes engineers and inspectors were at the factory watching the action
I guess I am fortunate. Own a 2018 Buick Envision with almost 80,000 on it., but I do have the turbo 2.0L engine. No problems yet. No repairs needed. Just maintenance and taking care of it. This includes washing underbody during the winter to prevent salt corrosion which I see on this video on this car is definitely happening (rust everywhere under the engine bay).
Hey Eric O, remember the days before computers ran everything? Back when each auto manufacturer had their own proprietary diagnostic connectors, OBD 1, when you pulled codes out of a ford with a test lite and you had a paper clip bent to short out the last two pins on the right side of a GM diag plug and count the money light flashes?
I feel your pain, buddy. In my line of work, the TVs get crappier every year too. They are designed to be put together ONCE, so it's easier for the monkeys on the assembly line. Lots of one time use clips that snap off etc...
Awesome video! You get to learn some of the strangest things when you aren't trying to!?! They probably lost one sensor and when they lost the other, they finally had it looked at.
Loose connectors can have several causalities but one not mentioned is cheap/weak materials used to make the female contact that 'relax' over time when exercised by big temperature differentials, vibration and other environmental factors.
That is similar to the way I tested air bag systems years ago. Once had a GM van that was in an accident. The passenger side air bag deployed but the driver's didn't and this was a frontal crash. The clockspring in the steering wheel had a bad connector at the airbag. When watching live data and the connector shorted at the airbag side, instead of zero volts the display was showing a slow increase in voltage. A new clockspring fixed the problem. Good one Mr. O. On to part 2.
Wow crazy. I would have been afraid to short those to ground, but glad to know they are ok. I thing you have to be in the seat also to get them to activate. I thought maybe a trip to wilberts for the connector !!
Yes Eric that happened to me in my 2009 Chevy 1500 (Chevy thunder)! Had a smaller doe hit my driver side door and deployed all my air bags. Front, side, and steering wheel and the only thing that happens to the door was a small dent. Pissed me off because I only got 40bls of the deer. It was small.
Eric, I absolutely love your videos! I learn something from each and every one and really enjoy the family interaction. You make us all feel like a friend looking over your shoulder... Thank you and Mrs. O for all you do! Love the after hours videos too!!! In this case, would it be a bad idea to install used sensors and connectors from Wilberts? The cost would be minimal but perhaps being safety equipment you don't want to take any chances like aftermarket sensors.
In my opinion, do what you feel is best on your own vehicle, but on a customer's vehicle, in this case, I think the best course would be new oem parts.
odd how the faults are crisscrossed between doors. But then that is GM I guess. Possibly a redundancy protection application to insure some Air Bags will always fire if system is corrupted electrically. Good video Thank you Mr. O
GM parts guys here. Your local dealership's parts department failed you. The part number for the front impact sensor connector and many others are often listed on the Master Elecrical Component List in GM's service information (which I know they have access to) rather than the parts catalog. For future reference the GM part number is 13585852. It's readily available (not backordered 🙂) and substantially cheaper (around $15-$20) than the one you ended up using (around $89).
Hey Eric...I see terminal fretting on forklifts too like you had on the L/F impact sensor.. It causes speed, height and temp senor faults for me.. I work with fairly new machines and nobody has been probing these things..I chalk it up to cheap metal for the fitment issue for the L/F connector..Great diag bud..
I believe, shorting bars is the name given by manufacturers at the diagnostic module connector, they connect two sensors, two air bags with a jumping bar at the module. Usually I cut the wires to get a true ohm reading. And fix them afterwards. That's why you may get two different codes from different sensors.
2021 GMC Canyon! Customer wanted aftermarket tow mirrors installed. Spent most of my time messing with the door panel clips way to go GM. New cars are great until something goes wrong.
13585852 is the GM part number for that connector. More than likely someone went after that sensor mistaking it for the code that was set for the side impact sensor and spread the terminals out.
The cross cross setup kind of makes sense if your trying to save a couple of pennies. The module needs multiple sensor to trigger within so many milliseconds to trigger the airbags, if the left side airbags deploy the right side airbags would effectively be locked out. I don’t know if there are 2 or 3 sensors on each side, if 3 then even if rear door is tripped due to opposite side impact the 3 rd sensor could still provide the 2 impact detection to trigger that side airbag.
I had two front sensors bad on a Mercedes, and could not believe both would fail at once. So, I learned a bit about them. Inside of the sensor, there is a “diagnostic resistor” across the two wires. That is how the controller can tell if the circuit is open or shorted. If the resistor opens, the code will set for an open circuit. You can test this with an ohmmeter on the sensor, which depending on the vendor seems to give between 1k and 75k of resistance. If the value is too low, it will complain about a short circuit. Failing as a short can also happen if the sensor detected hitting something according to some sources I read, like if the car is hit while the key is off. Both of my sensors were open circuit. I bought two used ones and both of those showed some resistance and the problem was fixed when I installed them. Because I was curious to see how two of them died at the same time, I opened one of the sensors to see what was up and found that the plastic had failed to seal well and let the brine into the part where the circuit board was and ate away the connection from the connector. Of course not all sensors may work this way, but in order to detect whether a circuit is open or shorted to ground or 12V, the cheapest thing to do is have a resistor to ground in the sensor and a resistor pulling up to VCC in the control module and looking for the expected voltage on the wire. This voltage detection works for switched, communication (eg CAN), and analog circuits, so I would be surprised to find anything else.
The diagnostic resistor should never 'open'. It's there as a diagnostic tool and there as a prevention of a zero ohm short to ground that could then burn wires, blow fuses and wreck havoc without it. The logic circuit reads that there is this resistor in series with the sensor. When there is a short in the impact sensor, all the logic circuit senses is the resistor - which also limits current. If there is an open circuit in the impact sensor, the logic circuit reads infinite resistance.
@@kell8603 Yes, it shouldn’t open, which is why they are broken. If the resistor opens there is no danger, since that is the same as the wire was cut or the sensor was unplugged. The voltage on the wire will float to the supply voltage of the pull up resistor in the module. If it shorts to ground, there is no danger since the only voltage is from the air bag module through the resistor inside of that module. The sensor only has the signal wire and a ground wire. No fuses will blow and wires will not burn on a short to ground or an open circuit. Both of these are common failures in signal wiring that modern cars detect and set codes for. The resistor I mentioned was not in series - it was in parallel. There was also another component that looked like a diode, a set of contacts, another two terminal part I could not free from the potting, and a magnet. Since I found the reason for the open right away, I did not spend more time on it to trace out how these other components were connected. In the working circuit, the module resistor is fed a voltage (probably 5V) on one terminal and the other terminal connects to the wire and the input circuit of the module. The other end of the wire has the sensor with the resistor to ground inside. The two resistors in this way make a voltage divider. If the supply voltage is 5V, and both resistors are the same value, the signal wire will normally sit at 2.5V. The module input can measure that against higher and lower thresholds, such as 0.5V and 4V. If the wire is over 4V, the circuit is “open”. If it is less than 0.5V, it is “shorted”. This is not necessarily exactly the resistances and voltages, but this is how it looks in the schematics and descriptions I found. Some sensors are more fancy and have other features to determine if there is a fault, but this crash sensor I took apart was amazingly simple for how much they cost.
The sensors are probably sharing the same ground inside the airbag module. That is kind of "common" since the PCB is cheaper and less complex. So if you would open up the module you will pretty sure find those two pins going to one internal ground. And then the criss cross makes sense because if you would put both right side sensors (front and rear) on one ground you would loose a complete side in impact detection in a fault case. Making this criss cross you would at least have the chance that an impact will be detected - if the front fails you still have the rear and vice versa
Eric, The factory manual discusses problems with terminal degradation at the sensors with some repair tips (dielectric grease?) The manual also indicates that some of the sensors have a common ground within the SDM. So, I think your in the right track. The SDM is under the center console. I had an Equinox where my daughter would spill drinks in the car resulting in intermittent SRS Codes. I have a 2017 Envision with 130K have not had any SRS problems. I don't understand how the connectors can all of a sudden go bad.
In addition, the manual indicates that these impact sensors will not initiate air bag deployment. They will only provide information to the SDM which uses multiple inputs to make the decision to deploy the air bags.
David, to which "factory manual" are you referring? Is it Equinox-specific, or something more generic? Do you have the exact name and some reference number, please ?
Wondering if the diagonal sensor connection has to do with the potential rotation effect from an impact on one corner. A hit near the drivers door activates that bag as the passenger would be forced into that door but if that same impact would also cause the car to rotate in a clockwise direction it would cause the right rear passenger to impact the right side. Pretty smart setup if you consider the rotation effect from a cornering impact. Just a wild ass guess from a retired cop with no mechanical skills but a lot of report taking experience. lol
Glad I know how to scan my own cars! Going back to having a OBD1 diagnostic on a laptop computer (about 1990). I was SO proud when I trapped an intermittent fault (O2 sensor flatlined and then came back) that the dealer couldn't duplicate!
Was thinking you might go for another junkyard walk to Wilbert's U-Pull of Bath for this one if some of the parts were unobtanium due to the strike, but they might not have anything this new in the yard.
Eric O luv you videos, what would happen if you use the f/r sensor to check the side ones, it looks as if they have the same conector. keep up the good work
Man when you clear codes at the 6:00 mark I heard that pow, an kinda thought the air bags went. 😅😅😅 Guessing someone was doing tires in the other bay. LoL
I think you made a good diagnosis, Eric. I'm anxious to hear and see what you find, We've heard that story before about Buying a wiring harness to get the connector, I'd like to know who you talk to about getting the aftermark connectors, if you would please. Good job thank you
I'm guessing the left front and the right rear and visa versa are interconnected electronically perhaps in a accident involving a T-Bone or a side front or rear quarter impact the control module will deploy both side air bags. More then likely it will go off of how much resistance is sensed between its shared sensors. This could allow lighter or more forceful deployment depending on what the parameters are in its equation for each side of the vehicle. This is just a guess. I'm not a computer geek.
The deal is everytime you figure something out that 2-3 other shops looked at Then you just gained a customer forever! Then they spread the word and you grow. I run service out of truck (powersports and water toys)and I have no storefront and no advertising and I stay very busy. But after 44 years Im thinking of calling it quits Im tired and just keep few old customers.
Always enjoy learning from different sources, I visit regularly and thank you for providing a logical approach to diagnostics, have you had to deal with ford tailgate harness issues camera(s), electric latch/lock Intermittent or inoperative.
When I do the gm door panels, I pull the felt off, it just slides out then use a pry tool for the push pins to get the metal clips out then put the metal clips into the door first then slide the felt into the door then snap the panel back on. Easy as pie
Great video. I agree with most about spreading connections with a voltmeter. On a separate note......... I SAY..... FIND A GOOD CHARITY, SET UP AN ONLINE AUCTION FOR YOUR GULF HAT. ! WHO WANTS ERIC'S GULF HAT ??
A guess. Are the split sensors maybe for redundancy? If you lose one sensor for some reason the other corner sensor on that side will probably still operate the air bag. If you lost the full side your protection would be completely lost.
I was thinking that too, but SRS systems are so sensitive, they will disable themselves if any part of the circuit is faulty. If the SRS light is on, all airbags are disabled by default. The crisscross sensing is probably for side impact sensing, so the car can tell if its side or rear 3/4 hit.
Makes sense if you get hit in right front it will push left rear of car into left rear passenger hence sets off right front and left rear airbag just a thought the one with bad pins maybe affecting the whole thing
You might be on to someting with your thery, they probably both share a linier voltage regulator each. You would think being an airbag system each sensor would have its own separate power and ground supply but idk.
I have a 2000 Toyota and a 2007 Chevy. The SRS light came on. No codes. I was stumped and just tried to disconnect the connector and put it back in. Wala! No more MIL light on both vehicles.
Great video and a perplexing situation with the crossover association. I'm surprised you didn't try a little swap tronics to verify wire integrity and parts performance. Merry Christmas to you and yours!
If I remember correctly, the system has to have two of two or two of three sensors triggered to set off the airbag, so if one connection is bad, it will set off the code for the other also. So in the front, if you fix the one bad one, the other should go away.
I was thinking that the reason that the two air bags are connected ( left side and right rear or right side and left rear) has something to do with the way the car will react when hit from the side.
Here I was thinking that we were all going for a ride along to Wilberts for some good 'ol 2nd hand fixy upy stuff! That was bizarre(& now I'm 2nd guessing myself) because SRS related Wiring(inside the car at least) is all Yellow over here.
I think my guy for redundancy, it has an x pattern in the wiring to detect impacts. Now in a logical sense, it would work as the module would be able to detect if its just a short/open or if you've been hit in the broadside of you vehicle. great video as always
That loose connector could be a classic example of people front probing forcibly with meter probes.
Exactly what I was thinking too Clive, especially since the locking tab was already released!
Clive, I hate it when people do that, just like a drees, just because you can make it fit, doesn't mean you should.
@@philmerrifield1163 Same with those dang yoga pants, or leggings.
chinese started minimising wires, sizes, wire is measured as a square amount or round, not sure which, but the chinese make it the smaller.. so your wire gauge is wrong. now car manufactures do the same, everything minimal, so,,it dont last & it breaks..buy pre 90 cars,, built correct..even wall plugs, are now made of sht alloy,,not copper.. same as power trans lines, alloy, rubbish,,.
I agree @BigCliveDotCom
Eric O, get yourself and 2 ohm resistor when your jumping airbag connectors. We used to use those on a breadboard, to test wire harnesses in place of air bags and impact sensors. This allowed us to test harnesses without risking lighting off airbags, and it would fool the control module into thinking the module or sensor was present. We built protoype harnesses for OEM development, this is how we tested them before installing them into vehicles.
I like Eric's procedure removing the door panels. Aggression without Excessing. He respects the customers equipment, not breaking things. Common sense goes a long way in auto diagnostics.
Common sense... Regarding the way modern cars are assembled/manufactured... I don't know any more.
Too much proprietary garbage!!
Whenever I see you using one of the red plastic trim tools I sent you a few years back , it puts a little smile on my face.
You are the best nobody takes us to the junkyard with them love your work
"I'm not a big electronics guy"...
You do a darn good job of faking it! Long time fan, Eric. Love the videos!! 👍👍
Nothing better than waiting on your vehicle to warm up on a cold northern Michigan day when a SMA video pops up.
Thanks Dr. O👍
What part of Northern Michigan are you from?(me Ironwood)
We visit my wife’s family at the farm they own in Michigan. I never go in winter it’s to cold for me. Colorado is not nearly as cold. Also the roads in Michigan are pure ice. Stay warm brother.
Mr. O. is on hunt, yet again, to solve the elusive Envision sensor mystery. Will the new sensors fix the problem? Is Mr. O. on a wild goose chase? Will the lovely Mrs. O. grace us with an appearance? Can Mr. O. get the doors back together without the use of naughty words? Stay tuned for the next episode!
Good recap😂😂
As the plot thickens dun dun dun 😊
I liked the watching soap, too.
Same time, Same Bat channel.
"And what about Betty Lou at the diner"?😮
Some manufacturers do not allow srs wiring repairs if there is soldering or wire cutting involved. Toyota and Lexus are the most strict. You can look in their position statements to find out. Only legal option is to replace the harness in that case. Mopar sells repair kits for theirs and if you use anything other than that, if an accident happens and the system doesn't work coz you repaired the srs harness with something other than their kit your probably in hot water. Food for thought, working in the insurance repair industry the last few years has shown me a lot of technicalities i never thought of
Yeah we were never allowed to repair damaged SRS or airbag wiring in the body shops, which sucked, because it did hinder a lot of repairs that would have been economical. However legally we were not allowed. Wasn't worth the headache at our shop.
@dropinbiking92 I do it every day lol. I also replace a ton of harnesses with Asian manufacturers. Good money but terribly wasteful on their part. It comes down to resistance or probability of failure and someone suing the auto maker
GM actually had a recall on the R/V vans to remove a connector under both seats, and solder the wires to by-pass the connector. Then, they had a recall to inspect the previous techs work. It turned into a cluster f@ck. I found SRS wires simply twisted and taped!!!! Oh and if the next guy had to remove front seats, he would have to cut the wires. WTF GM!?!
@@scrappy7571 My GM-H built in AUS has connectors to allow the seats to be removed maybe someone thought of that here.
Honda for example refer to SRS harnesses as having measured resistance, and so no alterations are allowed by splicing, soldering or cutting of any SRS wiring.Having all the connectors, loom or tape etc in yellow denotes them as specific to the SRS sustem. Also when you remove a connector it automatically shorts itself internally until the latch is retracted and it is reconnected to a sensor.
Hope the owner approves the repair and we get a part 2. Always love these electrical diag videos. Something I always want to improve myself with and you are helping me with your videos!!! Thank you for always making videos of cars that come into your shop!!! Hope all is well with you and also the family!!!! Love the channel!!!!
Always fascinating, Eric…your videos about diagnosing tough problems are case studies in logic just as much (or more) than mechanics. Thanks for the education!
Regarding the loose fit of the connector on the LF impact sensor, it might have been caused by someone attempting to read voltage at the connector with a DMM. I caused a similar problem with the ABS system on a truck I used to own by probing the connector. I had inadvertently widened the socket and caused an open circuit to be detected by the system. I had to use a dental pick to bend the socket back to its normal shape, which fixed the problem.
If you think about it, the reason for the sensors setting a code on the opposite side and the door behind it is simply to give the vehicle the ability to sense a side impact where one of the sensors is working at all times on one side of the vehicle. It is a way of producing redundancy in the system and saving lives because it you linked both sensors on the same side into a common circuit, if one quits you lose the second and thus allow that side of the vehicle to have no ablity to sense an impact.
I would like to think they all link together in the airbag module so if one activates all do.Then that way you have saftey covered on all corners.
@@LesReevesyou think or you don’t think 🤷🏻♂️ like gm has been for a decade now. If no one is sitting in passenger seat. That side of airbags are not activated 😉😉💁♂️😂
I hope you figure out wiring of impact sensors, I'd like to know. Great video
Nothing like a SMA video in the morning when I can’t sleep, mainly cause I’m on a stay vacation.
I don't think I've looked at the subscriber mark in a while. 850K! Way to go Doctor O!
I work at a GM dealership body shop and my standard method for those door trim panels is once I get the panel off, the glass seal just slides off the metal clips then you can easily remove them individually and insert them back to the edge of the door and push the glass seal back onto them. Also a quick pass with a propane torch will bring the sticky back to that barrier adhesive.
Never thought about reheating those. 👍
That's a great idea about heating those seals. Beats getting out the duct tape Thanks for the tip.
@@pontiacsrule8761 it works great you just have to be careful, it’s a fine line between softening up the glue and melting the plastic, I usually make like three fairly quick passes and it evenly warms the glue without damaging anything.
GREAT video, as always. It makes sense if the sensors in opposite corners are related. If not physically, at some level within the SRS module. If a car is hit on a corner (hard enough for the airbag to deploy), the person sitting in the opposite corner will likely smack their head, if their airbag doesn't also deploy.
I was thinking the same!
Should not all deploy if the impact is hard enough to set one off ?
Not in more modern cars, they only trigger the ones for occupied positions if the impact was high enough at those sensors.
That makes no sense. If you are sitting on the left side of the car and someone is sitting on the right side of the and the car is hit from the right, the person on the right will have their head smashed into the side of the car as the car is pushed towards them. The person on the left is going to be pushed towards the center of the car as the car is being pushed away from them. So, no, the person on the opposite side of the car isn’t going to smack their head against the air bag on their side of the car.
@@LTVoyager When the car's movement stops, the person opposite from the impact actually could impact the door on their side as they will still have momentum. This is how whiplash occurs during a head-on or rear-end collision.
Using a DMM with the standard probe tips can certainly cause damage to the connectors especially when the contacts a smaller than the probe tips.
When working on micro electronics in our meter shop, we had probe extensions that went over the standard DMM probe tips that reduce the tip of the probe by half the size.
Eliminating connector damage by forcing/spreading the contacts apart.
Eric O is so thorough with his diagnostics 👍🏻🏴
Love them GM cars! 13 codes...My Dakota is 23 years old,no codes-go figger
Built when Mercedes engineers and inspectors were at the factory watching the action
'Her indoors' has a thing that vibrates, great for finding intermittent connections
I guess I am fortunate. Own a 2018 Buick Envision with almost 80,000 on it., but I do have the turbo 2.0L engine. No problems yet. No repairs needed. Just maintenance and taking care of it. This includes washing underbody during the winter to prevent salt corrosion which I see on this video on this car is definitely happening (rust everywhere under the engine bay).
Hey Eric O, remember the days before computers ran everything? Back when each auto manufacturer had their own proprietary diagnostic connectors, OBD 1, when you pulled codes out of a ford with a test lite and you had a paper clip bent to short out the last two pins on the right side of a GM diag plug and count the money light flashes?
Hell. I don't know and is why I am watching you. I absolute love following you down these rabbit holes. You should take me hunting...
I feel your pain, buddy. In my line of work, the TVs get crappier every year too. They are designed to be put together ONCE, so it's easier for the monkeys on the assembly line. Lots of one time use clips that snap off etc...
I like that you tell me what you're thinking and why you're thinking it.
This ride on the diagnosis express was very interesting. I hope the customer wants to go for the repair.
Awesome video! You get to learn some of the strangest things when you aren't trying to!?! They probably lost one sensor and when they lost the other, they finally had it looked at.
The air bag system has always been a mystery to try to figure out to me thanks for the video
Was hoping for a Wilberts run, but still a great start to my Tuesday.
Loose connectors can have several causalities but one not mentioned is cheap/weak materials used to make the female contact that 'relax' over time when exercised by big temperature differentials, vibration and other environmental factors.
That is similar to the way I tested air bag systems years ago.
Once had a GM van that was in an accident. The passenger side air bag deployed but the driver's didn't and this was a frontal crash.
The clockspring in the steering wheel had a bad connector at the airbag. When watching live data and the connector shorted at the airbag side, instead of zero volts the display was showing a slow increase in voltage. A new clockspring fixed the problem.
Good one Mr. O.
On to part 2.
Wow crazy. I would have been afraid to short those to ground, but glad to know they are ok. I thing you have to be in the seat also to get them to activate. I thought maybe a trip to wilberts for the connector !!
Yes Eric that happened to me in my 2009 Chevy 1500 (Chevy thunder)! Had a smaller doe hit my driver side door and deployed all my air bags. Front, side, and steering wheel and the only thing that happens to the door was a small dent. Pissed me off because I only got 40bls of the deer. It was small.
that thing is a GMH Holden Captiva in Australia and mechanics love them and I'd never own one in a fit.
Typical Eric O modesty. "I'm not an airbag guy at all" but continues to give some of the best info on the system ever put out on video.
Carol just bought me those glasses last week for an electronics repair.
Eric, I absolutely love your videos! I learn something from each and every one and really enjoy the family interaction. You make us all feel like a friend looking over your shoulder... Thank you and Mrs. O for all you do! Love the after hours videos too!!! In this case, would it be a bad idea to install used sensors and connectors from Wilberts? The cost would be minimal but perhaps being safety equipment you don't want to take any chances like aftermarket sensors.
In my opinion, do what you feel is best on your own vehicle, but on a customer's vehicle, in this case, I think the best course would be new oem parts.
odd how the faults are crisscrossed between doors. But then that is GM I guess. Possibly a redundancy protection application to insure some Air Bags will always fire if system is corrupted electrically. Good video Thank you Mr. O
Bob's your Uncle..loved that!
GM parts guys here. Your local dealership's parts department failed you. The part number for the front impact sensor connector and many others are often listed on the Master Elecrical Component List in GM's service information (which I know they have access to) rather than the parts catalog. For future reference the GM part number is 13585852. It's readily available (not backordered 🙂) and substantially cheaper (around $15-$20) than the one you ended up using (around $89).
Hey Eric...I see terminal fretting on forklifts too like you had on the L/F impact sensor.. It causes speed, height and temp senor faults for me.. I work with fairly new machines and nobody has been probing these things..I chalk it up to cheap metal for the fitment issue for the L/F connector..Great diag bud..
I believe, shorting bars is the name given by manufacturers at the diagnostic module connector, they connect two sensors, two air bags with a jumping bar at the module. Usually I cut the wires to get a true ohm reading. And fix them afterwards. That's
why you may get two different codes from different sensors.
2021 GMC Canyon! Customer wanted aftermarket tow mirrors installed. Spent most of my time messing with the door panel clips way to go GM. New cars are great until something goes wrong.
I've only just noticed the collection of drills in the background at the beginning of the video :)
13585852 is the GM part number for that connector. More than likely someone went after that sensor mistaking it for the code that was set for the side impact sensor and spread the terminals out.
The cross cross setup kind of makes sense if your trying to save a couple of pennies. The module needs multiple sensor to trigger within so many milliseconds to trigger the airbags, if the left side airbags deploy the right side airbags would effectively be locked out. I don’t know if there are 2 or 3 sensors on each side, if 3 then even if rear door is tripped due to opposite side impact the 3 rd sensor could still provide the 2 impact detection to trigger that side airbag.
I had two front sensors bad on a Mercedes, and could not believe both would fail at once. So, I learned a bit about them.
Inside of the sensor, there is a “diagnostic resistor” across the two wires. That is how the controller can tell if the circuit is open or shorted. If the resistor opens, the code will set for an open circuit. You can test this with an ohmmeter on the sensor, which depending on the vendor seems to give between 1k and 75k of resistance. If the value is too low, it will complain about a short circuit. Failing as a short can also happen if the sensor detected hitting something according to some sources I read, like if the car is hit while the key is off.
Both of my sensors were open circuit. I bought two used ones and both of those showed some resistance and the problem was fixed when I installed them. Because I was curious to see how two of them died at the same time, I opened one of the sensors to see what was up and found that the plastic had failed to seal well and let the brine into the part where the circuit board was and ate away the connection from the connector.
Of course not all sensors may work this way, but in order to detect whether a circuit is open or shorted to ground or 12V, the cheapest thing to do is have a resistor to ground in the sensor and a resistor pulling up to VCC in the control module and looking for the expected voltage on the wire. This voltage detection works for switched, communication (eg CAN), and analog circuits, so I would be surprised to find anything else.
Don't understand a word, Ken, but I'm always prepared to listen to someone who has INVESTIGATED rather than just stroking his beard and musing.
The diagnostic resistor should never 'open'. It's there as a diagnostic tool and there as a prevention of a zero ohm short to ground that could then burn wires, blow fuses and wreck havoc without it. The logic circuit reads that there is this resistor in series with the sensor. When there is a short in the impact sensor, all the logic circuit senses is the resistor - which also limits current. If there is an open circuit in the impact sensor, the logic circuit reads infinite resistance.
@@kell8603 Yes, it shouldn’t open, which is why they are broken. If the resistor opens there is no danger, since that is the same as the wire was cut or the sensor was unplugged. The voltage on the wire will float to the supply voltage of the pull up resistor in the module. If it shorts to ground, there is no danger since the only voltage is from the air bag module through the resistor inside of that module. The sensor only has the signal wire and a ground wire. No fuses will blow and wires will not burn on a short to ground or an open circuit. Both of these are common failures in signal wiring that modern cars detect and set codes for.
The resistor I mentioned was not in series - it was in parallel. There was also another component that looked like a diode, a set of contacts, another two terminal part I could not free from the potting, and a magnet. Since I found the reason for the open right away, I did not spend more time on it to trace out how these other components were connected.
In the working circuit, the module resistor is fed a voltage (probably 5V) on one terminal and the other terminal connects to the wire and the input circuit of the module. The other end of the wire has the sensor with the resistor to ground inside. The two resistors in this way make a voltage divider. If the supply voltage is 5V, and both resistors are the same value, the signal wire will normally sit at 2.5V. The module input can measure that against higher and lower thresholds, such as 0.5V and 4V. If the wire is over 4V, the circuit is “open”. If it is less than 0.5V, it is “shorted”. This is not necessarily exactly the resistances and voltages, but this is how it looks in the schematics and descriptions I found.
Some sensors are more fancy and have other features to determine if there is a fault, but this crash sensor I took apart was amazingly simple for how much they cost.
Mystery's a foot Watson.🔍 Should make for a must watch part 2.👍
The sensors are probably sharing the same ground inside the airbag module. That is kind of "common" since the PCB is cheaper and less complex. So if you would open up the module you will pretty sure find those two pins going to one internal ground. And then the criss cross makes sense because if you would put both right side sensors (front and rear) on one ground you would loose a complete side in impact detection in a fault case. Making this criss cross you would at least have the chance that an impact will be detected - if the front fails you still have the rear and vice versa
Hi Mrs. O. nice to hear your voice! Have a Merry Christmas!!
Eric,
The factory manual discusses problems with terminal degradation at the sensors with some repair tips (dielectric grease?)
The manual also indicates that some of the sensors have a common ground within the SDM.
So, I think your in the right track.
The SDM is under the center console. I had an Equinox where my daughter would spill drinks in the car resulting in intermittent SRS Codes.
I have a 2017 Envision with 130K have not had any SRS problems. I don't understand how the connectors can all of a sudden go bad.
In addition, the manual indicates that these impact sensors will not initiate air bag deployment. They will only provide information to the SDM which uses multiple inputs to make the decision to deploy the air bags.
Hey I got 17 with 90k on it, so far so good as well
David, to which "factory manual" are you referring? Is it Equinox-specific, or something more generic? Do you have the exact name and some reference number, please ?
Thanks for the connector experts link, never heard of them.
Wondering if the diagonal sensor connection has to do with the potential rotation effect from an impact on one corner. A hit near the drivers door activates that bag as the passenger would be forced into that door but if that same impact would also cause the car to rotate in a clockwise direction it would cause the right rear passenger to impact the right side. Pretty smart setup if you consider the rotation effect from a cornering impact. Just a wild ass guess from a retired cop with no mechanical skills but a lot of report taking experience. lol
It also adds some senor redundancy in the case of a rotational force event. Both sensors will trip indicating a rotational collision.
I feel like that scenario would be handled by software logic in the computer, instead of trying to physically wire the logic into the harness layout.
Hi Eric, as far as I'm concerned, you have the skills to diag and repair anything!!
Cris cross situation reminds me of brake circuits 🤔🏴
Glad I know how to scan my own cars! Going back to having a OBD1 diagnostic on a laptop computer (about 1990). I was SO proud when I trapped an intermittent fault (O2 sensor flatlined and then came back) that the dealer couldn't duplicate!
Drag issue on the front pins were probably caused by the "other guy" that was in there poking around. Those little pins are kinda fragile.
Great job as always. I appreciate your logic in tracking down issues rather than following the rabbit holes presented by OEMs.
Buick Thunder
Thank you for the video
Absolutely positively without a doubt yes !!! The dealer would break it and and do everything possible to pass it on to the customer !
Just like Christmas, NEW SMA video.
great job...ur my number one channel really enjoy all of ur content have a good day!
I'm hoping that the repair will include a trip to Wilbert's U Pull It for a sensor connector.
Hi Eric had same problem on Toyota turned out to be negative ground cable on battery was kinda loose love your videos stay safe
Was thinking you might go for another junkyard walk to Wilbert's U-Pull of Bath for this one if some of the parts were unobtanium due to the strike, but they might not have anything this new in the yard.
Ballenger Motorsports sells wiring connectors too.
Eric O luv you videos, what would happen if you use the f/r sensor to check the side ones, it looks as if they have the same conector. keep up the good work
It's interesting to watch you work through strange results.
Man when you clear codes at the 6:00 mark I heard that pow, an kinda thought the air bags went. 😅😅😅 Guessing someone was doing tires in the other bay. LoL
I think you made a good diagnosis, Eric.
I'm anxious to hear and see what you find, We've heard that story before about Buying a wiring harness to get the connector, I'd like to know who you talk to about getting the aftermark connectors, if you would please. Good job thank you
If Josh came up behind Eric and popped a balloon while he's testing it
😳
Josh would only do that if the lovely Mrs. O told him to :)
🤣
JOSH WOULD NOT BE WORKING THERE ANY LONGER...
I'm guessing the left front and the right rear and visa versa are interconnected electronically perhaps in a accident involving a T-Bone or a side front or rear quarter impact the control module will deploy both side air bags. More then likely it will go off of how much resistance is sensed between its shared sensors. This could allow lighter or more forceful deployment depending on what the parameters are in its equation for each side of the vehicle.
This is just a guess. I'm not a computer geek.
The deal is everytime you figure something out that 2-3 other shops looked at Then you just gained a customer forever! Then they spread the word and you grow. I run service out of truck (powersports and water toys)and I have no storefront and no advertising and I stay very busy. But after 44 years Im thinking of calling it quits Im tired and just keep few old customers.
Always enjoy learning from different sources, I visit regularly and thank you for providing a logical approach to diagnostics, have you had to deal with ford tailgate harness issues camera(s), electric latch/lock Intermittent or inoperative.
When I do the gm door panels, I pull the felt off, it just slides out then use a pry tool for the push pins to get the metal clips out then put the metal clips into the door first then slide the felt into the door then snap the panel back on. Easy as pie
Great video. I agree with most about spreading connections with a voltmeter. On a separate note.........
I SAY..... FIND A GOOD CHARITY, SET UP AN ONLINE AUCTION FOR YOUR GULF HAT. ! WHO WANTS ERIC'S GULF HAT ??
A guess. Are the split sensors maybe for redundancy? If you lose one sensor for some reason the other corner sensor on that side will probably still operate the air bag. If you lost the full side your protection would be completely lost.
Like split diagonal braking systems? I like your logic.
I was thinking that too, but SRS systems are so sensitive, they will disable themselves if any part of the circuit is faulty. If the SRS light is on, all airbags are disabled by default. The crisscross sensing is probably for side impact sensing, so the car can tell if its side or rear 3/4 hit.
Makes sense if you get hit in right front it will push left rear of car into left rear passenger hence sets off right front and left rear airbag just a thought the one with bad pins maybe affecting the whole thing
You might be on to someting with your thery, they probably both share a linier voltage regulator each. You would think being an airbag system each sensor would have its own separate power and ground supply but idk.
Hope this guy goes for the repair. Curious to see the outcome.
30:17 LOL. Also, it's flagging the front-driver airbag open. Maybe the rear-passenger sensor is bad. The criss-cross thing.
Awe, I thought it was time for a trip to Wilberts.................😎
Eric @ SMA - "Let me just go check service data real quick." All the viewers - "Let me just go check SMA youtube real quick."
lots of resistance checking going on with that plug mister o, you just said a resistance check would be useless ;P teasing of course.
That was great TV if listening closely. Gosh popping tires, while you on air bag sensors. 😅
Maybe the diagonal impact sensor faults when shorted are like diagonal brake master cylinder line circuits as a safety/redundancy thing?
I have a 2000 Toyota and a 2007 Chevy. The SRS light came on. No codes. I was stumped and just tried to disconnect the connector and put it back in. Wala! No more MIL light on both vehicles.
Great diag thanks for sharing Eric
Great video and a perplexing situation with the crossover association. I'm surprised you didn't try a little swap tronics to verify wire integrity and parts performance. Merry Christmas to you and yours!
If I remember correctly, the system has to have two of two or two of three sensors triggered to set off the airbag, so if one connection is bad, it will set off the code for the other also. So in the front, if you fix the one bad one, the other should go away.
I like your magnifier glasses, where did you get them? I am visually impaired, and could use a pair. Sucks getting old
super interesting video. I was waiting for the bags to blow.
Eric,
Great video - thank you! Please bring us along for the follow up.
Paul (in MA)
Good morning Eric 😮
I was thinking that the reason that the two air bags are connected ( left side and right rear or right side and left rear) has something to do with the way the car will react when hit from the side.
I am waiting for you to take on a hybrid or full EV with electrical problems. If others can do it, YOU can do it.
We don't even have those in our area
O....you mean like Ivan...😅
He likes a good challenge. Great kid.
That's what the three vertical stripes on the Buick Badge forecast.
Here I was thinking that we were all going for a ride along to Wilberts for some good 'ol 2nd hand fixy upy stuff!
That was bizarre(& now I'm 2nd guessing myself) because SRS related Wiring(inside the car at least) is all Yellow over here.
I think my guy for redundancy, it has an x pattern in the wiring to detect impacts. Now in a logical sense, it would work as the module would be able to detect if its just a short/open or if you've been hit in the broadside of you vehicle. great video as always