Diagnosing SRS-Airbag Service Urgent

[prwood]

For the past year or so I've had an error message in the DIM saying "SRS-Airbag Service Urgent." At first I thought it was because I had pulled a SRS related fuse without disconnecting the battery.

Thanks to [user=jonesg], yesterday I was able to hook my car up to VIDA and read off the error messages it contained.

Amongst other things, you can see two CEM- messages and two SRS- messages about the driver's and passenger's seat belt buckles. These messages came back immediately even after we used VIDA to reset all codes.

I am assuming the SRS errors are what is triggering the "SRS-Airbag System Service Urgent" message to come on. Can anyone suggest what to check for the seat belt buckle errors? (I hadn't even considered the fact that buckles have wiring, but clearly they have to if the car can alert you to passengers being unbuckled!!!)

[yagger]

Can you text VIN your car?

[mrbrian200]

Early MY2001(P1) or late (P2)?

If early P1:
With key on KPII, check for +12v at the belt buckle electrical connector on the Yellow/Violet wire.
If no, trace the circuit back through fuse 11C/36 and relay 2/30.

beltsV70MY00.JPG (56.68 KiB) Viewed 12260 times

If the fuse is blown, look for a short to chassis/ground in the wiring.
To test the buckle switches (only after a short to ground has been ruled out), simply place a jumper between the two wires, reset the codes and see if they come back.

[prwood]

Early MY2001(P1) or late (P2)?

If early P1:
With key on KPII, check for +12v at the belt buckle electrical connector on the Yellow/Violet wire.
If no, trace the circuit back through fuse 11C/36 and relay 2/30.
beltsV70MY00.JPG
If the fuse is blown, look for a short to chassis/ground in the wiring.
To test the buckle switches (only after a short to ground has been ruled out), simply place a jumper between the two wires, reset the codes and see if they come back.

P2.

[mrbrian200]

Ok. On the '01 late/P2 you should see 12V on the violet wires at the seat belt electrical connectors. Comes from fuse 11C/14. I can't tell from the diagram whether it's hot all the time or switched (relay/switch circuit would be CEM internal if that were the case).
Same basic diagnostic procedures would apply: if the fuse is blown check for shorts to chassis/ground, check the belt buckle switches by placing a jumper between the wires at the buckle connector, clearing codes to see if they return (if they don't return the belt buckle switches are bad)
On the P2 this violet +12v wire splits at a junction 4 ways after the fuse, one to each buckle and two run direct back to the CEM, presumably to monitor the supply feed.

[mrbrian200]

A note regarding the AP sensor fault. The pedal sensor incorporates 2 independent sensors (one PWM, one analog) as a redundancy to prevent unintended acceleration events. A DTC fault more often indicates one of these redundant sensor elements has failed. If the remaining functional element were to have an issue while you were driving behavior could be unpredictable. You really don't want let this go out of concern for safety.