Long story short- car purchased a year and a half ago with non functional seat heaters, dealer replaced seat bottoms to enable seat heating. Got car back with airbag light on. Was told "oh it'll be fine to drive while you wire in the heaters- they unplugged the seats with the battery connected."

Stopped in at independent shop yesterday just to get that light reset FINALLY... and the mechanic told me "there's no plug for the occupancy sensor."

I flipped my lid, removed the seat today. Sure enough, I have a car side plug that goes to an on-seat pigtail that goes... nowhere. Can someone identify which of these seat plugs SHOULD go to a heater, or at least tell me what i've got going on so I can troubleshoot without removing the seat covers to find out?

This was the unplugged connector. Should it be hooked to the sensor pigtail? if no, where's it go?



This is the other half of that wire- this is just odd...


I'm unclear if I have a coincidental failure of the fragile occupancy sensor, or there should be something plugged into that connector.

Thoughts? Every connector at the leading edge of the seat connected to the car correctly- but there's one large 3 hole connector in the harness on both sides connected to nothing, and this small gauge 3 pin connector on the seat going nowhere.

 

This thread (https://www.northamericanmotoring.co...s-and-06s.html) has a photo of the full complement of connectors on a 2006 passenger seat:



One more post and photo here: https://www.northamericanmotoring.co...94-post41.html
It seems clear that the passenger side has an extra white connector (not found on the drivers side) and it must be the one for the seat sensor. If yours isn't connected and you're able to clear all airbag warnings, I don't think the sensor system is activated in your car. Can you post a photo of your seat bottom surface? If it has stitching anywhere near the middle area, it is a 2002-2004 style seat that doesn't have a sensor pad.

What is the build date of your car (look on the door jamb sticker)? If you have a very early 2005 (built in late 2004), perhaps seat sensors weren't implemented yet. Without a sensor connected, you should have a constant warning light that cannot be reset.

BTW, I was looking back at your previous posts, and perhaps you missed it but there was a reply that explains your seat heater situation. Your seats had been swapped out: https://www.northamericanmotoring.co...did-i-buy.html

 

The funky shaped connector is the occupancy sensor plug. There is a TSB to replace the wires and connector which I think is related to the wires being too short and pulling the connector apart and causing an airbag light on. The sensors are flaky and the dealer doesn't fix them under a recall AND they charge $1400 to replace. The result is many people have gone into NSC Expert and turned the sensor off which makes the pass airbag go off in a crash instead of in a crash when the right weight person is there. In the case of the NSC Expert fix, the sensor must be unplugged to not get the light.

So the question is whether your sensor connector is unplugged because the shop forgot to plug it in, the seat slid forward and pulled it apart, or did someone modify an ABG sensor code and left it apart on purpose?

 

Hey man, thanks for the info! Yeah, I have spoken with the gentleman who owned the car at length- but he didn't see my post until well after I purchased the car and the dealer already agreed to "make the heaters work" instead of giving me a discount on the car.

Unfortunately, it now looks like I'm stuck in a really bad bad spot- the work the dealer did to fix the heaters won't actually suffice since they only installed half the element in each seat, they removed the weight sensor apparently so i've got a persistent light now, and it's been a year or so since they handed the car back to me. Crunch mode at work bit me hard here.

I am not amused.

[Edit: I just saw your comment about the seat stitching. I have a stitch across the center, but that shouldn't matter- they replaced the seat bottom leather to give me heaters and the seat foam itself has the occupancy sensor. I had no light before I took it in for service and it was on when I picked it up. Here's a pic of the car the day after I bought it- it had stitching then as well.
]

 

I'd be willing to bet the shop forgot. There's no evidence of the seat-side of that plug being present. it's not a matter of "oh, i can replug this", it's a "there's nothing to plug to." The car is 5/05 production, it should have had long enough wiring on the car side.

 

Your orphaned cable should have something connected at each end, and it is a mystery why either of them is missing.

Does the wiring bundle that comes out of the floor now have nothing extra that can plug into the white connector? If you had no airbag warnings before you took it to the dealer, the wiring must have been there and plugged in previously. I can't imagine how this wiring would go missing now. The seat heater retrofit instructions are here and it doesn't seem to involve removing or replacing existing wiring.

The dangling other end of the cable doesn't make sense either. As I understand it, a seat bottom should come with a heater element and sensor mat already attached. The dealer simply orders a seat bottom and installs it. They don't normally install a heater element or sensor mat separately from the seat bottom. So either the seat bottom is missing the sensor, or there's an extra wire still tucked inside it. If the seat bottom is missing the sensor mat, it can be replaced under warranty (2 year warranty for OEM parts installed by a dealer).

Whatever the case, the dealer installation was simply wrong. As a safety issue, it goes beyond simple incompetence. If you had a small child in the front seat and the airbag went off, the dealer could be liable. I would take it back to the dealer and have them do it right, even if it's been awhile since they did the work. It wouldn't hurt to talk to them.

 

Yep! It wasn't a mini dealer (i bought the car used) and they outsourced the work to a third party- said third party obviously didn't know what they were doing. I have a working theory (that could turn out to be totally wrong) that when I told them they could in fact get the seat covers to fix their problem they just ordered two of the part number I gave them which was the driver's side part number- they certainly never ordered the seatbacks to go with so they don't work anyhow, but now i'm worse off than I was before I started.

The problem is it's been a year, and the service manager I worked with has since retired- this is going to be an adventure. I hope I don't need to lawyer up.

 

While we have the pics up can anyone identify what the connectors are for?

 

I recommend you recode the computer to turn off seat sensor activation.

If the seat sensor is unplugged (or missing) you will get an AirBag light. BMW finally admitted to the problem with these and replaced mine under a recall.

However, in the two years I waited for the recall I reprogrammed the seat sensor to "nicht activ" (not active) and that made the light go out. I used INPA or some sort of computer software and it is easy to muck things up so you must be careful in the programming.

Good luck,
Peter