This might be a long shot, but have you considered the font passenger seat occupancy sensor? I have just recently got rid of the air bag light, in my car. There is a pressure mat in the passenger seat that detects if there is a passenger or not. From what i can understand, this determines the amount of air bags that are deployed in the event of an accident. When the pressure mat dies, it will throw the light up on the dash. This light is indicating that in the event of an accident, ALL of the air bags will deploy no matter what. The reason i bring this up is that maybe when you open and close the rear door it is disrupting the sensor in some way. My air bag light was on and off for months, then it just stayed on all the time. There is cheap and easy fix for this, which I stumbled across on YOU TUBE. I will try and give a more detailed explanation of how to fix the problem. This should really only take about 30mins to complete. You will require the following items:-

* 2 x 100 Ohm resistors
* 1 x 1N4001 diode (I used a 1N4004, which is close enough.)
* Heat Shrink tubing
* 1 x soldering Iron
* 1 x pair of wire cutters

Once you have all these items together, you can create what some people may call 'The seat occupancy sensor bypass'.

First of all, you will need to locate the sensor under the passenger seat. The easiest way to do this is to adjust the seat all the way forward and raise it as high as it will go.

Now for the fun bit... Lie on the floor of the rear passenger side and look up underneath the rear of the front seat. Right near your head there will be a small rectangular box approx. 70mm long x 40mm wide attached to the underside of the seat This is the sensor.

You will note there are wires going in and wires coming out. The ONLY wires you need to worry about are the BLUE and WHITE wires.

You will also note there is a plug with BLUE and WHITE wires attached to it. Disconnect this plug and have a pair of wire cutters handy. Hold the plug in your hand and cut the blue and white wires, leaving approx. 30mm of play between the back of the plug and where you are cutting, as you will need this to solder the bypass to later on.

Once you have done all this, you can peel yourself of the floor of the car and head into the workshop! (With plug and wire cutters in hand)

You will need to solder 1 x end of one of the 100 Ohm resistors to one end of the Diode. Then repeat with the 1 x remaining resistor on the other end of the Diode. There is a silver band at one end of the Diode this end will be connected to the BLUE wire in the future.

You can place heat shrink over the whole thing at this point, but be sure to mark on the heat shrink, which end the silver band of the diode was on. this is IMPORTANT.

Carefully bend this contraption into a 'U' shape, with the diode at the bottom of the 'U'.

Solder the free end of the resistor attached to the silver banded side of the diode to the BLUE wire hanging off the plug. Now solder the end of the other resistor to the WHITE wire.

Now you can now heat up the heat shrink and voila! Head back to the car, lie on your back and plug it back together! The sensor mat will now be disconnected from the sensor and hopefully this will rid the light from your dash!

I recommend that you have a quick look at this video on YOU TUBE How to bypass BMW Passenger Seat Occupancy Mat sensor for passenger Airbag - YouTube , to give you a better understanding of what i have just described.

Hope this makes sense and fixes your problem.

Cheers,

Ben