Hi Folks,

I know ground faults are the bane of this car's existence, so there's already a ton of posts, but i wanted to further pick your brains for one I've not seen before.

Before I started working through a whole group of grounds to find this one, has anyone had these two warnings pop up at the same time:

Passenger door open (LHD car)
Airbag light on

These started coming on and off simultaneously, sporadically at first, but now it's permanent. Biggest problem with the passenger door open warning is you can only lock the car with the key and internal lights stay on if you're not careful.

I've got the wiring diagrams and it seems to be either the grounds in the passenger foot well or the one under the passenger seat. The ones in the foot well feel sound and secure.

If anyone has seen this and can send me to the correct ground, I'd greatly appreciate it. If not, I'll start working through them and report out which one it is in case someone else has this in the future.

Thanks,

Chris.

 

I would suggest following one issue and not try to look for a common cause. At a glance, the SRS does not share any grounds with the passenger door switch. Do you know what code the ABS module is throwing?

By far the easiest issue to track will be the passenger door switch. It's a simple switch to ground from the FEM. Ground G10 is on the RH A-pillar (this will be under the dash, above the fuse box).

I would start with a visual inspection to see if any harness in that area has chaffed on a sharp edge, that may account for both faults occurring at once.

 

Thanks very much for the really helpful advice.

I looked around behind and above the fuse box for G10. There's the two large ground wires that join on the side of the fuse box. I took the fuse box out and rooted around with my boroscope, but couldn't see a ground bolt above it. There appeared to be a heavy gauge black wire way up behind the IP, but couldn't find an end. The only ground was where two smaller terminals bolt to the end of the magnesium IP. They were corroded, so I cleaned them up, but no improvement.
I did read the airbag codes and it showed these:

B2290 Occupant classification system status (front passenger side)
B2291 Status of occupant position system (front passenger side)
B2292 Fault in passenger seat belt buckle switch circuit.

I'd have to look at the wiring diagrams, but these may all be to the ground that's under the passenger seat.

I'd hoped that G10 might have been easier to get to, but I guess not.

Any further help from the above description would be really helpful.

Thanks again!!

 

The ground at the end of the IP brace should be G10. Door switch could be faulty, you'd have to find one of the harness connector PD16 and do a functional check. That may be completely unrelated to the SRS lights. PD16 is described as: 22-WAY / BLACK / CABIN HARNESS TO PASSENGER DOOR HARNESS - located CABIN / PASSENGER SIDE ‘A’ POST. In the schematic above, you would be looking for pin17 (black wire) to go to ground. You can check this with an incandescent test light connected to a battery positive. Should light when you touch it to pin 17. And then pin 22 goes to the FEM. If you ground pin 22 the car should see the door as closed.

G13 under the seat is used for the passenger seatbelt and occupancy monitoring, so that tracks. I have seen the under seat ground look okay and fall off as soon as you touch it.

EDIT: just realized, I assumed you meant front RH passenger door. However the right rear door shares the same G13 ground. If that is the issue then G13 would be the place to start. The previous schematic was for the front passenger door.

 

Thanks again for the really helpful detail. Well, as with anything, this isn't as easy as I'd hoped. Turns out that the passenger seat won't move to access the bolts to get it out. I can get to the rear two, but not the front. I've ordered a flexible extension for my Dremel so I can cut a small amount (1/2") out of the seat rail above the bolt to get a socket on it and take it out. I guess the lack of power to the seat would make sense though if that's the ground that's bad.

Will let you know when I've got it out.

Thanks!!

 

OK folks, we have a winner!!

After significant battling and fighting to get the seat out, I was able to gain enough access from under the back of the seat after removing the bolts and bending it up a few inches. From there, I could pull the split in the carpet around the heater ducting apart to see the ground, which is immediately to the right of the duct when looking from the rear of the car. As we guessed, the ground had completely corroded through and was just hanging there. At this point (and here's the important thing for those unfortunate folks who have to do this in future), you can connect a piece of wire from the ground terminals to anywhere you choose on the body of the car. If you do this, it will at least allow you to move the seat forward and backward to get to all four bolts to remove them and get the seat out for easy access to a repair. Once I had the seat out, it was easy enough to create a new ground point - I added about a foot of wire to the end of the terminals and grounded it under the rear inner seat bolt to avoid having to drill more holes through the floor of the car.

Problem solved, all lights have gone off and the passenger seat now works. :-)

So, as I said at the start of this post, for anyone who has these combined faults all at once:

- "Passenger Door Open" warning
- Airbag light on. Specifically after reading the codes, they all relate to the passenger seat.
- Passenger seat will not move

Your most likely cause is the ground under the seat, G13.

I hope this helps some poor soul out in the future so they don't have to go through all the red herrings I had to in order to get there.

Thanks to mhamilton for all of their extremely useful and detailed direction!!

Good luck!!