Backstory: 2003 R53. My airbag fault light never comes on. Not during start-up or self-test. Never. No codes for the airbag system are popping up on my scanner. I suspect something was cut, coded out, or covered up. If they were coded out, the light would still self-test I think, so I don't believe that is it. I pulled the instrument cluster, found electrical tape behind the airbag light, and removed it. Still no light. I checked pin 12 (airbag light wire) on the instrument cluster connector; it doesn't get power on start-up. The airbag fuse has power on both sides of it. I was working my way downstream when I pulled the driver's footwell panel and found this disaster. I assume someone cut a large pin connector out (likely due to moisture or corrosion) and crimped the wires back together with butt splices. I think I have a few issues here, and I need someone to confirm my thinking:

1.) Remove all the butt splices and replace them with solder sleeve connectors or reinstall a pin connector. It looks like that connector just attached the wires from the instrument cluster to the wires that go to the fuse panel.

2.) Continue to troubleshoot the airbag system. I'm thinking maybe the airbag control module (under the brake handle, I think?) is bad. All the connectors are connected under the seats. Perhaps the control module is completely disconnected? I don't understand why the light doesn't illuminate on the self-test unless the gauge cluster is faulty (I am unsure how to test that yet). Any further ideas on where to look would be helpful. I want the airbag system to work correctly.

3.) Send the BCM to ECUPros for testing. Everything in the car except for the clock and central locking works. Constant codes are:

01 solar sensor
02 Inside temp sensor
03 heat exchanger sensor
04 position- air distribution flap
05 position- temp mixing flap
08 fan inside temp sensor
09 motor- air distribution flap
011 motor- temp mixing flap80 power window driver
8c relay windscreen wiper
91 rear window wiper
93 heated rear window short circuit
94 windscreen wipers/ reset contact
AA turn signal flasher, LH, open circuit, or short circuit to ground
B5 blower motor short circuit to positive
00 DWA driver door open during arming
01 DWA passenger door open during arming
02 DWA engine bonnet open during arming
03 DWA rear lid open during arming

Pointers or confirmation would be super helpful to get this thing sorted. When I bought it, I knew the car wasn't looked after very well, but I didn't want to see it end up in the dump, so here I am.

 

Sounds like a bad-or broken Clockspring when the steering angle sensor was replaced and the steering wheel was disturbed (not locked straight ) ? This would break the Clockspring, tripping the airbag light on dash and overhead light , which disables the airbag & horn.

 

The horn still works though. And the airbag light doesn't come on at all. No Steering Angle Sensor faults either. Could a clockspring still be the culprit?

 

I would think the Clockspring is functioning properly .Ohm out all the red crimp connectors first . Then remove all the butt splices and reinstall with pin connectors …

 

In case anyone ever runs into this, I figured it out. The car likely had a driver's door leak somewhere along the line, which I assumed damaged the 40-pin connector in the footwell. One of the PO's decided to cut it out and then rewire it incorrectly using cheap butt splices. I went wire by wire with the schematic, resoldering all of them. Now, everything works as it should.

 

awesome find...
I was looking at all the buttconnectors and getting anxiety from it, geez...
glad you finally got it figured out..

 

Hahaha when I got the footwell panel off and saw that, I set my tools down, went in the house and grabbed a beer. That could've been way worse than it ended up being. I guess theres a reason they tell you to buy one with a reliable maintenance history.....

 

LMFAO 👍