Air Bag Light/module/sensor
 

I've had an air bag light on now for about two months and instead of bringing to dealer I want to trouble shoot myself first. Last trip to the dealer they wrote on my (outrageous) invoice requires module #001 542 30 17.($96.36) This does not appear to be a MB part. It looks light a module/relay number. Is anyone familiar with this module/relay and if so where is it located.

I have also found four relays under the seats, 2 driver side, 2 passenger side. Wondering if these are part of the seat belt system and a bad one may be triggering the Light. Upon inquiry at my local parts supplier he informed me they appear to be MB specific, and therefore "dealer only". I was going to switch these out if they only cost a couple of bucks each but I would like to confirm that they are even a part of the system and the potential problem before I pay a dealer a fortune for a $10 relay. They are Hella brand part #002 542 1219.

Any thoughts on this or any other trouble shooting ideas would be greatly appreciated. I would like to rule every possible thing I can out before I bring it in to be scanned. I understand a common failure is the driver seat pad sensor and hoping that is not the case here.

Oh yeah last thing, my dealer has since closed shop so can't even call them to inquire about what they found on the previous trip.

Thanks in advance.

I believe relays under seats are part of seat heating circuits, at least that is where the sound of clicking relays is coming from when you turn on seat heater. Two relays because of two heating coils in each seat, one ON for 50% of heat, both ON for full heat. Touch those relays and have someone (sitting on the front seat) turn on the seat heater to see of feel if it the heat circuit.