e30 AIRBAG Indicator Light

[moutraklas]

hello everybody...

My e30 (318i convertibe, 1992) is one of the few with driver's airbag. I thought i was lucky to have one of these cars untill the indicator light turned on and noone here (greece, athens) really knows what the problem is (i doubt they 've faced that problem before). Anyway, they 've checked the circuits for shortcuts, they 've found that the ring in the wheel has a problem, changed it but the light is still on. So far, not one, but two different mechanics (official BMW dealers) have tried the same thing. Nothing. Now, they tell me that the control unit is probably responsible. They can't check it for working but since they find nothing else... That's their way of thinking! I must add here that both of them did plug the car in the diagnosis but it does not "see" the airbag... noone really knows why but they assume it is just too old in technology (one of the very first airbag generations) and maybe because fitted so lately in the e30, the ECU was not designed to support the airbag system.
I try to find a control unit in used parts but its difficult. By searching in realOEM i discovered that there is an Impact Sensor somewhere in the car, as a part of the airbag system. Noone said anything about it... Could this be the problem? Does anyone know where is it located in tha car? Does anyone knows anything that could be usefull about the airbag system in e30? Has anyone faced a similar problem?

There are 3 months now i m trying to solve the problem... If anyone could help i 'd be gratefull!!

Thanks,
Tasos

[stevofthahill]

The real question is do you want a 15 year old air bag going off in your face? The simplest solution if this concerns you at all would be to disable the airbag and unplug the srs light. Many people with airbag wheels will switch out for non-airbag such as mtech I and II wheels, and this is the route they take. I don't know what the general consensus is on disabling the airbag, so without others chiming in, don't take my word for it.

[Ablice]

hello everybody...

My e30 (318i convertibe, 1992) is one of the few with driver's airbag. I thought i was lucky to have one of these cars untill the indicator light turned on and noone here (greece, athens) really knows what the problem is (i doubt they 've faced that problem before). Anyway, they 've checked the circuits for shortcuts, they 've found that the ring in the wheel has a problem, changed it but the light is still on. So far, not one, but two different mechanics (official BMW dealers) have tried the same thing. Nothing. Now, they tell me that the control unit is probably responsible. They can't check it for working but since they find nothing else... That's their way of thinking! I must add here that both of them did plug the car in the diagnosis but it does not "see" the airbag... noone really knows why but they assume it is just too old in technology (one of the very first airbag generations) and maybe because fitted so lately in the e30, the ECU was not designed to support the airbag system.
I try to find a control unit in used parts but its difficult. By searching in realOEM i discovered that there is an Impact Sensor somewhere in the car, as a part of the airbag system. Noone said anything about it... Could this be the problem? Does anyone know where is it located in tha car? Does anyone knows anything that could be usefull about the airbag system in e30? Has anyone faced a similar problem?

There are 3 months now i m trying to solve the problem... If anyone could help i 'd be gratefull!!

Thanks,
Tasos

LOL "I thought i was lucky to have one of these cars untill the indicator light turned on" I know the feeling.

We all have airbags on our 1991 cars and up.

Ask yourself if you want an airbag. You're supposed to swap out airbag units every 10 years, or so they say. If you don't want it I would suggest a MTechnic 1 wheel or 2 if you like. Those impact sensors are what triggers the airbag : if you want to mess with those it's up to you, but I hear once the bag blows you replace everthing: control unit, bag, and wiring.

[VROOMCP]

PM me. I have an Airbag control panel from my 90 325is. I also have a the steering wheel.

David

[AlpineIS]

With the exception of early 1990 models, all '90+ models were fitted with driver side airbags.

Even though these systems are gen 1 airbags old (and are reccomended for inspection every 10 years), every e30 equipped with one and involved in a frontal impact that I have seen at junk yards have deployed bags. So they do work. Of course, whether they deploy with stored fault codes is a different story.

My '90 had the blinking light but I know what triggered it. After much research the only useful information I gathered was to find the control unit and disconnect the harnesses in order to reset the light. I decided it wasn't worth the effort and I switched to a non-SRS check panel.

I don't know much about airbags but it is difficult for me to understand why the dealer would replace the clock ring if their system cannot even communicate with the control unit. Even if you can determine the clock ring defective by visually looking at it, you would still need the proper equipment to reset the light. It is pretty clear that they cannot do the job correctly either because they lack the knowledge or no longer have the correct equipment to do so.

To answer your question...the impact sensors are located just forward of each front strut tower. They are rectangular and orange in color.

If I were you I would disconnect the harnesses from the SRS control unit and give that a shot first before you source a replacement.

[DaveSmed]

From what I understand about the SRS system, once the control module sees an open in the gas generator circuit, it sets a permanent code in the module. Only way to get the light to go away seems to be to replace the module, as even dealerships seem stumped by the system, and they were supposedly the only ones able to reset it. I believe it is a deploy code that sets as the module assumes open=gas charge detonated. Stupid design, but you said it yourself, the system is quite primitive.


There are a few different codes that look like they SHOULD trip with the bag simply unplugged (or clockspring broken) but those codes should also be resettable by dropping power to the control module. It is a shame, since i'm sure the system would still perform perfectly fine in a collision, I hear about the GM systems from the early '70s (1971 was the first year I think?) still working to this day, much to the surprise of owners who didn't know their car had one until they needed it.

[Modena NYC]

Bringing this back from the dead as I have the same issue in my E30...where exactly is the ABS control module?

[AlpineIS]

It's located underneath the dash on the left side under the headlight knob. The SRS module is there also...they face each other top/bottom.