Just confirmed this worked on an E30 318is!! Thank you SO MUCH!!!!!!
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. Thanks for posting this!
I can verify that this procedure works on my 91 850i. I did some repairs on the gauge faces and triggered the srs light. I tried counting the seconds 4 times with no joy. Then I tried with a stopwatch and bingo, light went out. Timing is specific!!
The above procedure for re-setting the SRS light et cetera works on my 1992 325i e30 Cabriolet, Siemens module 5WK4 026 (BMW part number 65771382904). To reset the SRS light, I rigged wires from pins 1 and 6 in the diagnostic connector under the hood to where I was sitting in the driver's seat. I then installed a switch to connect and disconnect pins 1 and 6. I too used a stopwatch and was very precise when opening and shutting the switch. Counting aloud did not work.
I can also read codes via the under the hood diagnostic connector (shorting pins 1 and 6) and watching the above-the-rearview mirror SRS light blink. See detailed instructions at https://www.r3vlimited.com/board/sho...d.php?t=173007 .Like others said, for re-setting the SRS light et cetera one has to clear the cause of the fault first.
I found that the reason I was getting codes, and the SRS light was lit, was that the 1992 BMW's airbag needed replacement. This causes code ""Driver's airbag power supply wire faulty." For this scenario, I used a dummy resistor and reset the SRS light using the following steps:
-- Disconnect the battery.
-- Remove the small cover on the bottom side of the steering column.
-- Disconnect the airbag connector that is underneath the small cover.
-- Purchase a resistor of 3.6 ohms, 1/4watt from a local electronics shop. I think other sizes between 2 ohms and 5 ohms will likely work as well.
-- Install the resistor in the connector's female end. This fools the diagnostic module into thinking a working airbag is installed. It clears the fault the diagnostic module was seeing.
-- Reset the codes using the procedure given in the first post of this thread.
After the initial six second lamp test, the SRS light stays off. I am now shopping for a new airbag. Or I may try to take the old one apart (carefully) and see if there is anything obvious.
Here's a writeup of my troubleshooting approach: https://sites.google.com/site/hondal...roubleshooting . It does not use any of those expensive, special "BMW Special Tools."
Great work, legoman67.
I am going to attempt this to clear my SRS light. I am an electrical novice so please forgive me. Unless there is a jumper somewhere I can buy, I figured I'd make one like some others have with a switch. What size are the pins?
'91 850i 6spd
Just worked on a 92 525i. Thank you Legoman
What did you use for the jumper?
I tried it yesterday and it did not work for me. I took long wire, put one end of raw wire right into pin #15 under the hood. Ran it to an on/off switch to control from the drivers seat and then to the ground post in the engine bay.
I just twisted the wiring together, and haven’t tried soldering it
This just worked for me as well, 1991 850i 6-speed. I accidentally disconnected the SRS connection and had the light on for awhile. I used a test light inserted to pin 15 and ran the clamp end to the ground post on strut tower drivers side. Use a watch unless you have a very good internal clock
Here's a simple schematic that will simplify the SRS read/reset (switch selected) for early E31 (mine is a 91 850i with Siemens 5WK4 027). This connects to the diagnostic port in the engine bay.
To read SRS codes this simply holds RxD low for a few seconds (when ignition is turned on) and then releases. If you then wait about 20 seconds the SRS light will flash out the codes which you can decode with the info in this thread.
SRS reset holds RxD low (when ignition turned on) for 5 seconds, releases it for 5 secs and then pulls it low a 2nd time for 5 seconds and then releases. After about 20 seconds you can turn off the ignition, remove this circuit and SRS should be reset.
You could of course do this manually as suggested in the first post.
I've used this a few times on my own car and it works well. The pot allows adjustment to exactly 5 seconds (I'm not sure how critical this is).
It's not my neatest work... I threw it together with salvaged parts.
I was hoping to communicate directly with the SRS module since it has TxD/RxD but the Siemens 5WK4 027 is not compatible with Inpa or DIS. It does not appear to use the same wake up protocol as the EML, DME, EGS as I tried every combination and none produced a response. I'm sure it is possible but I can't find any details on the protocol for this ECU so have to make do with flashing codes...
Attachment 689556
Attachment 689557
Since I do experience some issue with my srs light I am expert in resetting procedure
IMO even 6 sec will not work. I have wires connected to diagnostic port with switch on the end so I can make a bridge from the cabin. I have also stopwatch running to be exactly on time. After resetting I wait around 10 seconds and start the engine.
I tried the procedure using the 20 pin diagnostic port several times using a switched jumper and iphone's stopwatch with no luck. My timing the 5 sec hold may not have been sufficiently accurate to allow a reset or the SRS module may not be wired to the 20 pin diagnostic port. I did not try to access the SRS module under my dash.
Update: Tried procedure again and was able to reset SRS light. This time I connected switch to pins 15 and 19. Previous attempts had been to pin 15 and chassis ground. Didn't think ground connection made a difference. Also, tried to accurately flip switch at 5 sec intervals, etc. Thanks to all who responded to this and other posts dealing with the SRS light/other troubleshooting.
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