1993 940 just acquired.

The SRS is inop, light will NOT reset. Shows 3 codes for:

1.Steering wheel contact, I replaced the clock spring, the one there was overwound. The bag is new.

2. Left belt tensioner. Appears good, not deployed, has continuity.

3.Right belt tensioner, also looks undeployed, and has continuity.

So, the SRS doesn't want to reset! Five seconds, and nothing! Reads the codes fine but that's it.

Grateful for any ideas...

 

I had this problem with my 92 740. Apparently the SRS system ages out, there is a warning notice on the b-pillar door strike.
The good news is, the system still functions fine; the 740 rear ended another vehicle and all systems performed normally (airbag and seatbelts)

 

Have you tried the reset procedure? The ones I reset (years ago) were finicky - would usually not get it reset the first time. I would use a small metal terminal attached to a length of wire with a alligator clip on the other end, trying to get a good ground on the lighter base.

(below copied from turbobricks)

"Apr 6, 2012

• #11

For resetting the light, this has worked for me twice on my 1990 240 (after pulling the steering wheel and disconnecting the airbag, which triggered the fault code).

1) Leave the ignition in the accesory position, engine off
2) pry the SRS light out of the instrument panel
3) Attach a probe and lead to the exposed terminal on the back of the light module (that is, there will be a wire attached and then a metal contact where it looks like another wire could be attached. I'm referring to the latter)
4) Ground the lead for a few seconds and then wait. Lights will blink several times to indicate the fault code.
5) After the code has been displayed, quickly ground the lead three times with a fraction of a second in-between each grounding. I think the light will blink a few times before it goes out. You may have to try this several times before it works (at least I did).

I think I found the instructions for this at Brickboard, as well as a listing of the fault codes. If yours won't reset you might want to take a look there to make sure I'm not "mis-remembering" and also to get a readout on the code yours is throwing."

 

Thanks! I got it done, it was the main SRS sensor just giving erroneous signals. Luckily I had one laying around that did the trick.