u/Rocco_o

Hey everyone,

I’m still fighting with the airbag system on my 1996 BMW Z3 (1.8 M44) and could use some guidance.

I finally bought an SRS reset tool and now I’m getting the fault:

“Firing circuit belt tensioner passenger side.”

The previous owner had already messed with the wiring under the seat. The original yellow connector was cut off and replaced with heat‑shrinked wires. One of the wires (pink) was corroded, so I cut everything open and temporarily connected the wires with WAGOs just to test.

The airbag light still won’t clear.

My question:

What’s the best way to track down this fault?

Should I check resistance at the tensioner itself, inspect the wiring further back in the harness, or is there a common failure point on the Z3 that I should look at first?

Any advice on how to properly diagnose the firing circuit for the passenger belt tensioner would be greatly appreciated.

Thanks in advance.

I am so frustrated with my z3

I have a 1996 BMW Z3 (1.8 M44) and originally had the fault “Ignition circuit not closed” for the seatbelt tensioner. The previous owner had the tensioner unplugged. After reconnecting it, I cleared the fault and the scanner showed no errors, but the airbag light stayed on.

When I checked under the seat, I found that the previous owner had cut off the original yellow airbag connector and replaced it with heat‑shrinked wires. One of those wires, the pink wire. Is corroded (green, brittle copper). I cut the shirnkedbeires and connected them with WAGOs for now.

I don't have any idea what to do now.

Any help??