The previous Japanese owner of my car had taken the warning bulb out of the cluster and filed the hole with black mastic, presumably in frustration with the airbag fault. I have now fixed the system, however it was hair pullingly exasperating.
I have had a nightmare with my drivers seat pre-tensioner, cleaned the connections, checked continuity across the circuit from the SRS control module, carried out the youtube featured resistance checks, replaced the pre-tensioner, all to no avail. I ended up installing the repair cable set 61129118122 as per the BMW technical service bulletin and worth noting that it uses entirely different connectors - no dash light finally!
Also worth noting that I checked continuity across the section of loom i replaced together with the seat element of the loom after I had chopped it out of the car and it was all ok, even if you played with the connector. My theory is that the wires in this section of loom had degraded over the years to the point that they were significantly increasing the resistance and as such the SRS diagnostic check was reading that the circuit was out of tolerance. I'm no electronics expert so can't say more than that, but if i get the same problem with my passenger seat pre-tensioner, I'm not going to mess around and I'll just go straight for the repair cable.
