Hi there, the most common fault with seat mats is high resistance / open circuit.
If the fault is not currently present it is common that the connecter, a small 2 pin plug under the seat towards the rear of the base, had a poor contact. This is usally caused by something under the seat pushing against it. I have found all sorts of items wedged under seats!
The mat can tested with a resistance check by seperating the mat from the cars loom and checking its resistance. Make sure you disconnect the battery before carrying out any work on the airbag system.
It is common for these mats the fail and are replaced by removing the seat base cover and replacing the mat that sits between the foam and the cover. I think they are around £60.
Hope this answers all your questions if not feel free to reply.
Regards Phil...
Hi,
I will get resistance reading for you, and message back about this time tomorrow ok
Phil
Hey,
That is a shame because i tested a mat at work today for you.
I got a reading of 1.1ohms not pressed and 1.08 ohms when mat pressed.
I always thought it was a mat fault.
Hope you fix your car
Regards Phil, an accept will be much apreciated.
bmw tech
ata tech, nvq3, city and guilds 3