Air Bag Help Needed

javis20

Active member
 Hershey, PA USA
Car is 2003 E85. I'm getting an air bag fault light. Sometimes I can reset it with IMPA and mostly I cannot. Cutting to the chase, I believe it's being caused by the frequently mentioned connector at the battery. It's been reported that there is a connector in the battery compartment that gets a poor connection and requires re plugging. Anyway can someone post a picture of the connector location so I can resolve the problem? Also, is there a procedure? Does the battery have top be disconnected first?
 
Seat looms and connectors, seat occupancy sensors and control modules are probably the most common causes to the airbag light. Never heard of battery related causes, except when disconnecting seat connectors and alike with the battery still connected. What error codes does INPA show?
 
Started with seat sensor, which i reset. But within a few weeks it came back, so I replaced the seat pad sensor. Again, reset for a few weeks, before it returned. So I purchased a plug to bypass the sensor. Again a few weeks and fault light again for seat sensor plus low voltage to pillars and other modules. Now it's at the point where it will no longer reset.
And yes, there is an issue with a plug. Apparently it's where the the system gets air bag system gets power.
 
WDS says that the occupancy sensor is powered via fuse F13, safety and information module via F45. Low voltage at several modules could, however, suggest bad battery or battery terminals.
 
javis20 said:
Cutting to the chase, I believe it's being caused by the frequently mentioned connector at the battery.

Never heard of the connector. Where have you seen it referenced?

Assume you’re constantly reading faults before you clear? What’s it saying? If it’s not the seat, could be one of the airbag b pillar modules? Or maybe even the airbag ECU?
 
Many faults including pillar, I'll look for the list. Anyway here is one of several threads about the connector...
https://www.bimmerfest.com/threads/airbag-light.655016/
 
The power distribution to the modules is really simple: Battery positive to F100 (left to the battery, 250A), from there to the fuses behind the glove box (incl. F13 & F45). SIM and B-pillar modules are powered from F13 & F45 and share a common grounding at X1106 located in the footwell, next to the speaker. They should show the voltage drop if you have a power distribution issue from battery or battery connections. Corroded battery shoes and battery ground cable (incl connection to chassis) are quick things to check.

There's a connection from the B-pillar satellite module to the safety battery terminal in the battery compartment, but it is not for powering the modules: The satellite monitors the power cable shielding for shortcuts and also in the event of accidents cuts the power. The system is described in WDS.
 
Here are some of the codes I was getting. I should note there were some battery problems due to a failing alternator. I have not tried to reset the airbag faults since replacing the alternator.

93b3 Passenger airbag stage 2
93b8 Passenger airbag, driver
93ba Seat belt catch driver
93c2 Seat matt occupancy
93c8 airbag sensor driver.
 
A failing battery or alternator can cause all sorts of gremlins. Airbag codes usually don’t clear themselves, so after replacing the alternator you could try to clear those error codes and see if they come back at all. If they do, then the SIM would probably be the best bet, as Rockhopper suggested.
 
The cars on the other side of the country right now. So I either have to find him a BMW shop out there or send him my laptop and remote into it with Teamview.
 
I don't know but when I pulled mine out the connector was corroded. Same thing with the pillar modules.
 
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