Source to learn about SRS (airbag) repair? Help troubleshooting

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Aug 19, 2015
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I'm repairing a vehicle I bought at auction and having some trouble finding info about the SRS system to repair it. Seems like the dealers and techs scare people away from repairing these systems due to airbags being explosive.

1) the truck is far away from a dealer. Local body shops say they send them out to the dealer and won't work on the system. Even if I didn't have negative history with the dealer and they were local, I'd want to figure this out myself anyway. This is an off-road work truck that won't travel far from base. I'm half considering to leave the airbag control unit unplugged but I want to see if I can fix it first.

2) The truck was hit on the side and the steering wheel airbag deployed. The airbag and leads have been replaced (clock spring was still functional), and the airbag control unit was sent out for reprogramming. After getting it back, all codes cleared except for a side impact sensor. I have the factory software that is capable of clearing SRS codes, but my Zurich code reader also clears them. To troubleshoot, I switched impact sensors side to side, but it the original code remained active. For certainty, I bought a new sensor to make sure it wasn't the sensor.

3) Next, I bought a used airbag control unit from an identical vehicle that had a blown engine and wasn't in an accident. After clearing codes, the same passenger side airbag code remained. So it's not the sensor, and I can see how it would be the airbag control unit if both units get the exact same code. This leaves me with the harness, or something I haven't thought of. I'm not sure if the harness plugs can go bad after a deployment, or where to look now, as I can't find a guide for testing the harness. I know this is delicate work, because if you resistance test the wrong thing it can deploy the airbags.

Anyone have resources or experience that could help me figure this out? The factory manual says to replace the sensor, then replace the airbag control unit. Both have been checked and it didn't solve it.
 
Sorry to be the first one in and not have a definitive answer but I seem to remember reading ....somewhere in some vehicle tech blurb/excerpt that the STS code was stored in the ECU.
That'd put it 'upstream' of anyone's airbag control unit.
Highly proprietary?
Good luck.
 
Many times the harnesses will need to be replaced in the event of deployment. RCMs included.

Disconnect all the wiring from the module and the impact sensor and do some testing with your multimeter. Be sure to check the pins on the connectors.
 
Many times the harnesses will need to be replaced in the event of deployment. RCMs included.

Disconnect all the wiring from the module and the impact sensor and do some testing with your multimeter. Be sure to check the pins on the connectors.
I swapped in another RCM and it gets the same code, so I suspect it's the harness. I'll try to do some testing today and check the pins.
 
The replacement module will need to be programmed to your vehicle - verify the service manual instructions but I am pretty sure it says to.

Please let us know the year/make/model and we can help you better.
 
The replacement module will need to be programmed to your vehicle - verify the service manual instructions but I am pretty sure it says to.

Please let us know the year/make/model and we can help you better.
The replacement module functions except for the same code the original had. 2008 Toyota Tundra. If it needed to be programmed, wouldn't it not function? According to the Toyota Tech I talked to, a new unit would be plug and play. Maybe he's wrong, but this unit certainly seems to be if it shows only one code, which is the same code as the original had.
 
Modules will have a base software installed - its the calibration files and VIN number that get flashed. Most times most functions will work but the flashing or calibrations make the module work exactly for a certain application.

Looking in my Pro demand it says that the passenger seat sensor must be calibrated when replacing a module - haven't seen any specific mention of flashing the SRS module but clearly says not to use modules from other vehicles - a common rule but doesn't mean we can't. There is a lot of good information there to sort out your issue...lots of reading too lol. I'll read deeper when i have some more free time and report back.
 
Modules will have a base software installed - its the calibration files and VIN number that get flashed. Most times most functions will work but the flashing or calibrations make the module work exactly for a certain application.

Looking in my Pro demand it says that the passenger seat sensor must be calibrated when replacing a module - haven't seen any specific mention of flashing the SRS module but clearly says not to use modules from other vehicles - a common rule but doesn't mean we can't. There is a lot of good information there to sort out your issue...lots of reading too lol. I'll read deeper when i have some more free time and report back.
Curious if you found anything?
 
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