From the E31 forum of BF: This only works on Early E31, start of production to 09/93 With SIEMENS 5WK4 027 (65771382905) modules. This module is also found in some E23,e24,e30,e32,e34, and e36, procedure should work for those as well. This worked for mine even when DIS/INPA/Autologic, and all those others failed to communicate.

1. Turn the ignition switch to the off position.
2. Install a jumper from in pin #15 of the engine diagnostic connector to ground.(Since this is awkward to do in the timing given in this procedure, i used a small screwdriver and tapped into pin 6 at the orange x74 connector behind the glovebox, either will work)
3. Turn the ignition switch to the on (run) position but, do not start the car.
4. After five seconds, disconnect the jumper.
5. Wait another five seconds.
6. Reconnect the jumper
7. After five seconds, disconnect the jumpers.
8. Wait five seconds after disconnecting the jumpers.
9. Turn the ignition switch off.
10. Start the car. The air bag warning light should clear after approximately 10 seconds. If the light does not clear repeat the procedure. If, after three attempts, the light does not clear, there is most likely a problem with the air bag system which needs to be repaired.
by legoman67; 05-25-2014 posted in the E31 forum BF, do it at your own risk.

Q&A:
This only works on Early E31, start of production to 09/93 With SIEMENS 5WK4 027 (65771382905) modules. This module is also found in some E23,e24,e30,e32,e34, and e36, procedure should work for those as well. This worked for mine even when DIS/INPA/Autologic, and all those others failed to communicate.
1. Turn the ignition switch to the off position.
2. Install a jumper from in pin #15 of the engine diagnostic connector to
ground.(Since this is awkward to do in the timing given in this procedure, i used a small screwdriver and tapped into pin 6 at the orange x74 connector behind the glovebox, either will work)
3. Turn the ignition switch to the on (run) position but, do not start the car.
4. After five seconds, disconnect the jumper.
5. Wait another five seconds.
6. Reconnect the jumper to ground pin #6 (or from pin #15 in the round OBD port under the hood???).
7. After five seconds, disconnect the jumpers (I'm assuming you mean only one jumper either Pin #15 of the round OBD port under the hood, OR the alternative Pin #6 of the orange x74 connector behind glove box, and not 2 jumpers?.
Legoman, can you see what I wrote in color and clarify for me please. Just wanna make sure there is only one jumper wire needed. either the #15 pin in the round OBD port under the hood, OR the alternative pin #6 of the x74 orange connector under glovebox.I remember doing something with a wire and the OBD port to reset the oil/service interval light too.
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yes, only 1, they are both the same wire, just different points to reach it at, i edited to first post to eliminate confusion
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by radlaw: legoman: how did you ever come up with this solution? It couldn't have been trial-&-error!

legoman: i found it in an old PDF file that was for another car, i just modified it slightly to correct the pin numbers and plugs.
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by acheson850i: After start up the SRS light on my car (CB42262 Prod 02/91) blinks for about two-3 minutes and then stays on permanently while the car is running...is it supposed to? If not should I give this a try? I presume the light should be off. The light should not stay on. It should go off within 10 seconds of the car starting.

answer legoman: Remaining on means there is a fault code stored in the module. Most likely from removing the steering wheel without taking proper steps to avoid triggering it. This procedure should work for you.
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Pinout by Timm
<img src="http://www.meeknet.co.uk/e32/dc.jpg">

by legoman: the X74 plug is an 8 pin orange plug that plugs into the SRS module(1 of 2 that plug into the module, the other is a 6 pin). the module is located behind the glove box on the E31. You have to remove the kick panel, under tray, and upper and lower glove boxes to get to it. Unless your dash is already a part, or you are familiar with removing the glove box, i would just get a buddy to work the ignition for you while you do the jumper from the diagnostic plug pictured above.
Also in response to earlier posts about reading the codes. It doesnt actually state how to trigger the blinking, it just says it can be done:
You can retrieve the fault codes from a Siemens controller if you wish. The controller will blink out a series of codes through the SRS light in the Active Check Control panel. The first number that it blinks is the number of stored codes. Next, will come a long blink. Then the fault codes will be blinked. The fault codes are separated by a long blink. Each fault code is blinked as four digits as follows:
1. Light flashes 1 to 4 times for the first digit.
2. 3 second pause.
3. Light flashes 1 to 4 times to indicate the second digit.
4. 3 second pause.
5. Light flashes 1 to 4 times to indicate the third digit.
6. 3 second pause.
7. Light flashes 1 or 2 times. (once = Short-time fault; twice = Long-time fault)
The table below provides the fault descriptions for early Siemens controllers
Here is the table:

Blink Code-Fault-Fault Description
111 1 Front Sensor Left Closed 1 time
211 2 Front Sensor Left Closed several times
311 3 Front Sensor Right Closed 1 time
411 4 Front Sensor Right Closed several times
112 5 Front Sensor Left Closed permanently
212 6 Front Sensor Right Closed permanently
312 7 Front Sensor Lead Left Leaks against positive
412 8 Front Sensor Lead Right Leaks against positive
113 9 Front Sensor Lead Left Leaks against ground
213 0A Front Sensor Lead Right Leaks against ground
313 OB Front Sensor Lead Left Short circuit against positive
413 OC Front Sensor Lead Right Short circuit against positive
114 OD Front Sensor Lead Left Short circuit against ground
214 OE Front Sensor Lead Right Short circuit against ground
121 11 Front Sensor Lead Left Break
221 12 Front Sensor Lead Right Break
321 13 Front Sensor Lead Left Excessive resistance
421 14 Front Sensor Lead Right Excessive resistance
322 17 Ignition Capacitor 1 Insufficient capacitance
422 18 Ignition Capacitor 2 Insufficient capacitance
123 19 Transition resistance to ignition capacitor 1 Excessive
223 1A Transition resistance to ignition capacitor 1 Excessive
323 1B Ignition Circuit 1 - Driver Airbag Leak against positive
423 1C Ignition Circuit 2 - Passenger Airbag Leak against positive
124 1D Ignition Circuit 3 - Passenger Airbag Leak against positive
224 1E Ignition Circuit 1 - Driver Airbag Short circuit against positive
324 1F Ignition Circuit 2 - Passenger Airbag Short circuit against positive
424 20 Ignition Circuit 3 - Passenger Airbag Short circuit against positive
131 21 Ignition Circuit 1 - Driver Airbag Leak against ground
231 22 Ignition Circuit 2 - Passenger Airbag Leak against ground
331 23 Ignition Circuit 3 - Passenger Airbag Leak against ground
431 24 Ignition Circuit 1 - Driver Airbag Short circuit against ground
132 25 Ignition Circuit 2 - Passenger Airbag Short circuit against ground
232 26 Ignition Circuit 3 - Passenger Airbag Short circuit against ground
332 27 Ignition Circuit 1 - Driver Airbag Break
432 28 Ignition Circuit 2 - Passenger Airbag Break
133 29 Ignition Circuit 3 - Passenger Airbag Break
233 2A Ignition Circuit 1 - Driver Airbag Insufficient resistance
333 2B Ignition Circuit 2 - Passenger Airbag Insufficient resistance
433 2C Ignition Circuit 3 - Passenger Airbag Insufficient resistance
134 2D Ignition Circuit 1 - Driver Airbag Excessive resistance
234 2E Ignition Circuit 2 - Passenger Airbag Excessive resistance
334 2F Ignition Circuit 3 - Passenger Airbag Excessive resistance
434 30 Failure Warning Lamp Short circuit
141 31 Failure Warning Lamp Broken filament
241 32 Control Unit Internal fault
341 33 Firing Order Correct -
441 34 Ignition Current Flowed
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Here is what I know: My 1990, E34 M5 has the same SRS control unit. My 1988, E24, M6 had an earlier model Siemens SRS controller that uses the same code reader/reset tool. I purchased the BMW SRS code reader/reset tool (88 88 6 621 290) that works on the Siemens SRS controller a long time ago because it was the only way to reset the Siemens SRS control in the early days (1990's). The Siemens SRS control causes a lot of consternation when it was first introduced because it was the first SRS control that required special tools to reset. Yours is the first post since I have been involved with BMWs since 1990 that indicates the Siemens SRS controller can be reset without special tools. As for reading the SRS flash codes; there are only 2 document that I am aware of, produced by BMW, that explain how to read the flash codes and only one document that defines the flash codes. The manual for the 62 1 290 SRS reader/reset tool only has the explanation of how to read the SRS flash code. The E30 Repair Manual (01 51 9 770 561) includes the SRS Troubleshooting in the Group 32 Steering and Wheel Alignment section. https://www.bmwtechinfo.com/repair/main/Index_cd3.htm
This manual on page 32-55.1 includes the Siemens SRS Control - HOW TO Read the SRS light flash codes and a section on flash code conversion into fault codes and fault code definitions. The SRS flash/fault code list posted here is a more comprehensive list that what is in the E30 Manual and includes SRS codes I have yet to find in any other official BMW document and believe me I have just about every official document produced by BMW.Just Having Fun,Rod...
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reply legoman: It is unclear what vehicle the directions i have were originally written for. not an official document.
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reply rod: The BMW OE reset tool 62 1 290, for the SIEMENS 5WK4 027 (65771382905) controller also works with the Siemens controller in the E23, E24, E28, E30, E31, E32, E34 & E36 vehicles up to 9/1991. Some of these cars also used a Cipro airbag controller but I believe the E31 only used the Siemens SRS controller. On the E31 this model Siemens controller was also only used up to 9/1991. Unsure what controller is used after 9/1991 , however the Peak R5/SRS scan/reset tool works on my 97, 850.It is also my experience that the Peak R5/SRS scan/reset tool is unfortunately not compatible with the Siemens 5WK4-025,027 or 035 controller.
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Question on this: I've read that pin 19 is ground so it stands to reason that you could use the jumper to connect pin 15 and pin 19 and that would work? 1993 740IL

reply legoman: yes, that would work

Posted by Rod/m6bigdog: The BMW OE reset tool 62 1 290, for the SIEMENS 5WK4 027 (65771382905) controller also works with the Siemens controller in the E23, E24, E28, E30, E31, E32, E34 & E36 vehicles up to 9/1991. Some of these cars also used a Cipro airbag controller but I believe the E31 only used the Siemens SRS controller. On the E31 this model Siemens controller was also only used up to 9/1991. Unsure what controller is used after 9/1991 , however the Peak R5/SRS scan/reset tool works on my 97, 850.It is also my experience that the Peak R5/SRS scan/reset tool is unfortunately not compatible with the Siemens 5WK4-025,027 or 035 controller. the later airbag modules (09/93 and up from what ive read) have no issues communicating with all the usual diagnostic tools(DIS, INPA, Autologic, PEAK, ETC).

reply legoman: The only 2 units i have heard of that will reset the early 5WK4 airbags are the factory tool you mentioned, and shogun's specially developed tool.
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wokke: didn't work on my 04/1991 850i.And the system should be ok because there was no issue before I swapped the wheel.
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legoman: The timing is very specific. I actually used the stopwatch on my phone to do it.

wokke: I ordered the tool from shogun and succeeded on two 850s. My own one plus a customer car having had the same issue like me.Also the SI rest works flawlessly. Thanks for pointing me to that product Erich.
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JamesM3M5: Just confirmed this worked on an E30 318is!! Thank you SO MUCH!!!!!!
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pturn: This worked for me first time! very very very happy. SRS came on due to instrument cluster removal w/o battery disconnect and key turn on (i knew better but long story). followed these instructions using a button switch and wires - hardest part is keeping track of what you should be doing. FYI my car is a 1991 535i (E34, M30), US.

the original thread is here
https://www.bimmerforums.com/forum/s...-Special-Tools!!!

From my checking the SIEMENS 5WK4 027 (65771382905) module was installed: 65771382905 Control unit airbag
From: 09/01/1987 To:- Weight:0.862 kg Price: $1179.58
Superseded by:
65778353598 (09/01/1991 ), nonexchangeable retrospectively
65778352763 (09/01/1993 05/03/1996), nonexchangeable retrospectively
65778369828 (03/01/1996 03/12/1998), Exchangeable retrospectively
65778374821 (09/01/1996 ), Exchangeable retrospectively
Supersedes:
65771379036 (10/01/1986 06/09/1989)
Part 65771382905 was found on the following vehicles: http://www.realoem.com/bmw/enUS/partxref?q=65771382905
3' E36   (11/1989 02/1998)
5' E34   (03/1987 12/1995)
7' E32   (10/1985 03/1994)
8' E31   (07/1989 10/1994)

on E32: Part 65771382905 was found on the following E32 vehicles:
7' E32, 730i, Sedan, M30, MANUAL, EUR, (GA31)
7' E32, 730i, Sedan, M30, MANUAL, EUR, (GA32)
7' E32, 730i, Sedan, M30, AUTO, EUR, (GA41)
7' E32, 730i, Sedan, M30, AUTO, EUR, (GA42)
7' E32, 730i, Sedan, M30, MANUAL, EUR, (GA71)
7' E32, 730i, Sedan, M30, MANUAL, EUR, (GA72)
7' E32, 730i, Sedan, M30, AUTO, EUR, (GA81)
7' E32, 730i, Sedan, M30, AUTO, EUR, (GA82)
7' E32, 730iL, Sedan, M30, MANUAL, EUR, (GC11)
7' E32, 730iL, Sedan, M30, MANUAL, EUR, (GC12)
7' E32, 730iL, Sedan, M30, AUTO, EUR, (GC21)
7' E32, 730iL, Sedan, M30, AUTO, EUR, (GC22)
7' E32, 735i, Sedan, M30, MANUAL, EUR, (GB31)
7' E32, 735i, Sedan, M30, MANUAL, EUR, (GB32)
7' E32, 735i, Sedan, M30, MANUAL, USA, (GB33)
7' E32, 735i, Sedan, M30, AUTO, EUR, (GB41)
7' E32, 735i, Sedan, M30, AUTO, EUR, (GB42)
7' E32, 735i, Sedan, M30, AUTO, USA, (GB43)
7' E32, 735i, Sedan, M30, MANUAL, EUR, (GB51)
7' E32, 735i, Sedan, M30, MANUAL, EUR, (GB52)
7' E32, 735i, Sedan, M30, AUTO, EUR, (GB61)
7' E32, 735i, Sedan, M30, AUTO, EUR, (GB62)
7' E32, 735iL, Sedan, M30, MANUAL, EUR, (GC31)
7' E32, 735iL, Sedan, M30, MANUAL, EUR, (GC32)
7' E32, 735iL, Sedan, M30, AUTO, EUR, (GC41)
7' E32, 735iL, Sedan, M30, AUTO, EUR, (GC42)
7' E32, 735iL, Sedan, M30, AUTO, USA, (GC43)
7' E32, 735iL, Sedan, M30, MANUAL, EUR, (GC51)
7' E32, 735iL, Sedan, M30, MANUAL, EUR, (GC52)
7' E32, 735iL, Sedan, M30, AUTO, EUR, (GC61)
7' E32, 735iL, Sedan, M30, AUTO, EUR, (GC62)
7' E32, 750i, Sedan, M70, AUTO, EUR, (GB81)
7' E32, 750i, Sedan, M70, AUTO, EUR, (GB82)
7' E32, 750iL, Sedan, M70, AUTO, EUR, (GC81)
7' E32, 750iL, Sedan, M70, AUTO, EUR, (GC82)
7' E32, 750iL, Sedan, M70, AUTO, USA, (GC83)
7' E32, 750iLS, Sedan, M70, AUTO, EUR, (GC85)