Airbag fault after dead battery

[DJ_57]

Back in April I was working out of town for 5 weeks.
I knew the battery would be low but it was dead. Not even the usual red blinking security light on the cluster or radio. I didn't bother trying to start it but instead popped the hood and hooked up a battery charger to the jump posts.
Horn honked weakly at first and cluster/dash lights kept blinking and flickering on and off so I decided it was better to pop the trunk, disconnect the negative cable, and charge the battery overnight that way.
I connected it the next morning and it started like a champ. Radio did its usual CD mech after having no power, clock at 0000 hours, but now I've got "airbag fault" that won't go away after multiple starts.

Disconnected battery and waited a while (I remember there being a sequence to do that before pulling airbag fuses). Then disconnected those fuses. 10 minutes later all connected and no difference. After key on, I get "airbag fault" message.

Anyone have any solutions that worked for them in this case? Please let me know so I can provide helpful hints to dealer technician, it's at the dealer now for other issues.


EDIT: fix below:
https://g8nation.com/showthread.php?...l=1#post624921

[Napalm]

Let me make sure I read it right.

Dead battery - hooked up a battery charger - but did it under the hood to the aux + terminal and grounded to the engine eye. Car acted up - so instead of disconneting you went to the back and pulled the negative battery cable off the battery. Let it charge overnight that way - and now you have a warning light.

First thing - I don't know where you heard or read the idea of pulling the negative battery cable while charging but that is very dangerous in general let alone on a modern car. Sorry you have an issue now but please don't do that again. It's unsafe for you and unsafe for the electronics on the car.

Now - things to check - internal fuses by the dr side kick panel. check anything ABS and of course also check BCM and ign fuses. I need a diagram. There is one in there for COmm - pull that one too. There is a fuse for the comms buss and that's the network between the modules. If the abs is getting off messages it errors out also.

Under the hood - there is another fuse panel - If I recall there is another ABS fuse and a Comms fuse there too as well as a BCM fuse. I would maybe check those.


However - what I think might have happened. While it charged with the negative battery cable untied - many of the electronics of the car lost their ground as they are made to use a floating ground. As such the current charging the battery came in from the front of the car - taking the path of least resistance, over the hours might have leaked though modules and might well have damaged some of them.

[DJ_57]

I got the codes from the dealer. Stored codes B0081 and U0170. Lost communication with PPSM, and No communication.
They cleared the codes and they immediately come back.
Sounds like the sensor module is a must-replace after reading on here, or is there a way around it?

[2SteelHorses]

DJ_57, did you ever get this resolved?

[DJ_57]

DJ_57, did you ever get this resolved?

Update: finally fixed.
Dealer quoted several hours to replace PPSM plus programming. They told me I could source the part myself and replace it myself, and they would be cool with programming it for $150.
I found module 92225594 (for my cloth seats) from Holmart in Australia. A NOS OEM part shipped to my door was less than $67 total after currency conversion. Cheapest online price anywhere else after tax and/or shipping shipping was still going to be over $350. Dealer was more than that.
Dealer allowed me to work on the car in their back lot with my own tools (very cool of them)
I followed the steps in this thread: https://www.g8board.com/forums/4-tec...lt-photos.html
I replaced module #92219364 with #92225594.
Since I was doing the work, and not the dealer, I took the extra 5 minutes and drilled out the 2 rivets and removed the 2 seat stops.
Reassembled everything. Of course, light and codes still present.
Dealer reprogrammed new module and performed test. All is well and the passenger module does work (#2 seat belt minder on dash, "ON" on rearview mirror with enough weight).
And now I can haul passengers that are over 5'10" comfortably. And for any doubters, YES there is enough slack in all harnesses for the seat to stop all the way back. It's amazing the amount of room now.
Upon further investigation by the dealer, the labor time was not several hours. They were looking at the wrong air bag module. The labor for the PPSM replacement alone was 1.2 hours, plus programming. I managed to do it (including the seat stops) in 40 minutes including all tools put away. Still saved a chunk of coin doing it this way.

I'm still bitching that GM doesn't acknowledge this. By their own part number change, it looks like internally they realized the old part failed. From my job experience, I realize you change revisions for minor changes, but you supersede part numbers when there's a major change in the part that you need to prevent the old part number from being ordered, usually due to defects or other issues. GM knows this. It's unfortunate that the entire SRS is disabled if one component throws a code. Based on how GM works, it's going to take multiple deaths and a NHTSA investigation before they ever acknowledge a failure.
But at least it's fixed.