Resetting airbags/no connection

[tantumaude]

A mechanic recently was installing my sump guard, took the car for a spin and somehow ended up unplugging the connectors from the steering wheel to the column. He's been fired since.

Anyways, this means I have an airbag light on due to this happening without the battery disconnected. Fortunately or unfortunately for me, the car has an S62 swap, and so I do not have the round connector under the hood, but rather and OBD2 port. I'm trying to reset the light, but all the tools and software both the shop and myself have tried can't handle an E34 having an OBD2 connection and won't recognise the SRS module.

Is there any possible workaround to this?

[CarterH]

Is the plug definitely plugged back in?

It might be possible to make it go away unplugging the battery overnight and maybe unplugging the SRS module too. I've heard sometimes unhooking the battery for about 24 hours can fix things like this.

[demetk]

What year/model?

[tantumaude]

Sorry, it's a 01/1995 540i/6 originally.

@CarterH: yes, I pugged it back in the day I got the car back. Horn was disconnected too.

I'll try to do what you suggested. Not sure I can leave it unhooked for 24 hours (daily driver), but will try.

[CarterH]

Well maybe not 24 hours but try overnight, that should be enough. It's not a guarantee that it will fix it but it's worth trying since it's free.

[tantumaude]

No luck, I'm afraid. I left the battery unhooked and the module disconnected for 22 hours. Light is still on.

[demetk]

Maybe take a look at the ETM for your car and see if you can do anything with the white/violet wire at the srs module that is usually connected to pin 20 of the datalink connector. I'd be tempted to install a datalink connector and connect power, ground and the white/violet wire in the correct places. Maybe a reset tool will then work.

On my 89 535 I was able to perform a manual reset of the srs light by switching the srs to ground a couple of times in a specially timed sequence that I found on the net. On my car the srs wire was connected to pin 15. Yours looks to be connected to pin 20.

[demetk]

Correction: Looking at the ETM's more closely I see years 89 through 95 all use pin 20 as the transmit signal and pin 15 as the receive signal at the datalink connector.

[tantumaude]

Thanks for the insight, I may just have to do that.

Insofar as I can tell, all my wiring that would normally go to a datalink connector has been routed through a CANBUS module and thereafter to the OBD2 connector. Getting to said wires is going to be quite the project.

[kalevera]

Correction: Looking at the ETM's more closely I see years 89 through 95 all use pin 20 as the transmit signal and pin 15 as the receive signal at the datalink connector.

This. I can't believe whoever built the car simply deleted the original diagnostic connector. How else were they planning on maintaining the rest of the electronics in the car?

It should be an easy fix once you get that connector back - most of the commercially available diagnostic tools can reset '95 SRS light (including plenty of the cheapy single function ones)...but it needs an actual reset, it's not going away on its own

[demetk]

Thanks for the insight, I may just have to do that.

Insofar as I can tell, all my wiring that would normally go to a datalink connector has been routed through a CANBUS module and thereafter to the OBD2 connector. Getting to said wires is going to be quite the project.

Are you able to see the other modules via the OBD2 connector?

This procedure actually worked on my 89. I wonder if it will work on the 95? Tap into the white/yellow receive wire at the srs module.

https://www.bimmerforums.com/forum/s...3#post28926233

[tantumaude]

Little update for today. I plugged in my trusty PAsoft 1.4, and surprisingly got a list of about 30 errors, all listed under the DME module. I didn't have enough time to check all of them, but a few had nothing to do with the DME (steering angle, pdc system, etc). I'm thinking perhaps I might find the SRS errors that way?