Trying to Eliminate All Warning Lights - Help!

[DKJimmy]

I'm trying to clean up the look on the dash of my 1990 750il, sorting through the warning messages on the check control as well as lights on the dash. Currently I'm trying to figure out how to diagnose and fix my SRS (airbag) and ABS lights that are on.

The SRS light came on since I changed out my steering wheel with a non-airbag Nardi wheel, but I mistakenly turned the key on before I wired in a 3.3k ohm resistor to the airbag plug to fool it. The ABS light will sometimes come on, sometimes not. It seems to come on more when it is wet outside.

I have BMW GT1 DIS diagnostic computer, but it will not read out either control units (SRS or ABS), it just says that the control units are not available/missing. Is there another tool out there to properly scan these control units, or can I disconnect the control units manually to reset them? I would still like to know what is causing the ABS light to come on, and I cannot use the manual test because my ASC light doesn't illuminate/flash to provide diag codes.

Any input is helpful, I know shogun waits in the shadows to answer my questions. Thanks

Pic for reference



Heres the wheel setup:

[Pelican Parts]

Take a look at the link below for the Bavarian Technic tool and it's features - it's specifically made for BMWs.

http://www.pelicanparts.com/catalog/...TEC-detail.htm

[shogun]

As for the ABS light: that might be a problem of dirty sensors, clean them and also check the wiring. I once had a ABS light on when a wire from the ABS sensor was damaged.
SRS: Not all tools work for the old E32 BMW, because it has the older SRS control module. For example the Peake SRS tool as well as the chinese made B800 work on cars built from 1994, but not built before. I am not sure if that Bavarian tool works on the SRS built before 1994 units.
I once sold SIR3 and BOA airbag reset tools, that work on all BMW from 1988, but sold out, I only have a last one on stock which I want to keep.
Maybe someone in your area has such a tool and can lend it to you. But the fault has to be repaired before resetting, otherwise the light comes on a again. So as you removed the airbag steering wheel and replaced it by a non airbag steering wheel, also there I have my doubts that you can delete the light permanently.

added:
Just for info on the Schwaben by Foxwell reader tool for use on pre-OBDII cars, comment from Greg: "This is a great tool, unfortunately, it does not work on my 1993 (1/93 build date). Since I have two OBD-2 BMW vehicles I plan to keep it. As this vehicle is pre-OBD2, I used the 20-pin adapter. The tool recognizes the car and displays the seven digit VIN so it appears to communicate with the ECU. It scans (both auto and separate systems) but most of the scan categories do not show codes or no codes and it simply displays a question mark. It did not recognize some major systems like the instrument panel and ABS and displays a message that the component is not recognized. Lastly, it does not enter the re-set mode to allow oil service updates, and it does not allow the removal of airbag fault codes. Bottom line: still looking for another tool for my E34."

[DKJimmy]

Thanks. Now that I think of it, i have a pre-sept 91 750il parts car as well as a 90 535i parts car, which all share the same SRS control unit. I will try unplugging the control unit first, then if no luck, hopefully one of the cars will have a good fault-free control unit.
I also tried your method with the jumper wire.
I put a 3.3k ohm resistor on the srs connector, which I also did to my 91 M5 when I installed an mtech II wheel and was able to clear the fault on that car and it never returned. It is my understanding that the airbag gives out a ~3.3k ohm output when plugged in, so that fools it into keeping the light off. I have done it on multiple friend's e34s as well, but not on e32.
As for the ABS, I have a feeling it may be a bad sensor, I will have to inspect the wiring.

[shogun]

In case of the ABS sensor: on my car the problem was the plug coming from engine bay, it meets the ABS sensor plug from the senor and they are plugged together front left wheel house. On my car the plug coming from engine bay was totally brittle and broken, they are not available as single plug. I had an engine harness from another parts E32 and soldered that plug with a wire pigtail in, otherwise you have to solder the wires front sensor to engine bay.
SRS: check on realoem which built years use the same SRS control unit.
For example my one has Control unit airbag up to 12/1990 65771382904
up to 11/91 65771378290 Control unit airbag From:09/01/1987 To:-
Superseded by:65778353599 (09/01/1991 — ), nonexchangeable retrospectively
Part 65771378290 was found on the following vehicles:•5' E34   (03/1987 — 12/1995) •7' E32   (10/1985 — 03/1994) http://www.realoem.com/bmw/enUS/show...74#65771378290

Interesting thread here, How To: GET and RESET Airbag Codes/SRS Light https://www.r3vlimited.com/board/sho...d.php?t=173007

[stacksandkate]

My ABS light was staying on...I went through checking all the sensor and wiring without luck. There is a relay in the main fuse box for the ABS, I took the relay out, poked around in it, sprayed some CRC in there and the ABS light has been working fine since.