Talk to me about the Passenger Seat Sensors....

[Shipkiller]

Tell me if I am wrong on how this works....

I sit down in my drivers seat, and the seat belt light is on. I clip my belt and it goes out.

Now when somebody sits in the passenger seat, the seat belt light should go ON again until they buckle their belt?

Am I right or am I screwed up again.

Right now NOTHING happens when someone sits in the passenger seat, so the problem I am having with the AirBag light might be traced to this...... and I might have to replace the seat pad sensor...

 

[ovrkll]

Don't know, never looked. :scratchhead: I will check it out tomorrow and let you know 8)

 

[Adam D]

I do know that once I put my rucksack on the passenger seat and it set the seatbelt alarm off mid journey.... scared me silly!

 

[Shipkiller]

I do know that once I put my rucksack on the passenger seat and it set the seatbelt alarm off mid journey.... scared me silly!

One more data point, pointing to a bad passenger seat sensor... Thanks.

 

[Adam D]

PS I only think it did it for the passenger when moving above 15mph.

 

[Shipkiller]

PS I only think it did it for the passenger when moving above 15mph.

Still, the car told you that something is in the seat and to buckle the belt.....

That was more info than what I had before.

 

[Wondermike]

Definitely a sensor on both seats

 

[enfield]

^^^ - yep, mine has a seatbelt sensor on the passanger seat and it does work....

 

[Shipkiller]

That's it. It must be the passenger seat sensor that is causing all the problems.

Now, I have to get on and get it replaced..... RealOEM does not show the sensor part number, but I did a casual drive by and will have to look harder this time.

 

[cj10jeeper]

Definitely a sensor on both seats

Is there actually a sensor in the drivers seat, as it's not possible to drive without someone sat in it? I thought it simply checked if the seat belt was fastened?

Spot on re a sensor pad in the passenger seat, of course..

 

[Shipkiller]

I am not sure if there is a drivers seat sensor in the seat. Looking at the electricals, it does not show a drivers seat sensor.
When I had the passenger seat out, I can see the wiring for the pressure pad sensor...

 

[Wondermike]

Definitely a sensor on both seats

Is there actually a sensor in the drivers seat, as it's not possible to drive without someone sat in it? I thought it simply checked if the seat belt was fastened?

Spot on re a sensor pad in the passenger seat, of course..

Good thinking :smart:

 

[DMike]

Tell me if I am wrong on how this works....

I sit down in my drivers seat, and the seat belt light is on. I clip my belt and it goes out.

Now when somebody sits in the passenger seat, the seat belt light should go ON again until they buckle their belt?

Am I right or am I screwed up again.

Right now NOTHING happens when someone sits in the passenger seat, so the problem I am having with the AirBag light might be traced to this...... and I might have to replace the seat pad sensor...

Shipkiller, when I recently swapped my manual sport seats to motorized M-seats I encountered lots of trouble, including missing wiring and a faulty passenger seat occupancy sensor mat (or a wrong kind of sensor mat, actually). AFAIK the driver's seat does not have a sensor mat. The sensor mat has changed over the years, pre 2006 used a separate detection module (aka SBE, a tiny black box under the passenger seat), and post 2006 sensor mats have the electronics built into the rear end of the mat. If unbuckled, the seat belt light should light up if approx. 12 kg of weight is placed on the seat, and after a certain speed has been reached (10 to 20 kmph if I recall right). A faulty sensor mat, detection module, or cabling should fire the SRS airbag light, which will stay on. You may also want to check the passanger airbag deactivation switch. I was able to troubleshoot the sensor mat by reading fault codes at the dealers, and ended up changing the sensor mat myself.

 

[Shipkiller]

DMike, thanks.

I have seen the SBE module, and checked all the connections to and from it.

If I get time before I leave on my trip, I will take the seat back out and try to do a continuity check on the seat sensor pad.

To answer your question on the deac switch, when I start the car, the passenger airbag deactivation light will come on for very brief period (normal I think) then go out. I can deactivate the airbag with the key switch and the light will then come on and stay on. It seems that part of the circuit is working...

Another pain is I cannot determine if the seatbelt detect switch works properly until I get he seat pad working... I have taken resistance readings on it but it is a Hall Effect sensor so the resistance is anywhere from 5K to 30K...

How much of a pain was it to change out the seat sensor pad?

I can read the fault codes, but I don't have a cross referance for them...

The fault code I get is either:

Safety and Information Module P13E6 (BMW Fault Code E6)
Safety and Information Module P13E7 (BWM Fault Code E7)

IKE/IKI/KOM P1120 (BMW Fault Code 20)