Page 2 of 2 FirstFirst 12
Results 26 to 36 of 36

Thread: HOW TO: Reset Early Airbag/SRS light. No Special Tools!!!

  1. #26
    Join Date
    Jun 2001
    Location
    Reston, VA
    Posts
    6,827
    My Cars
    88 M5 FOR SALE, E92 335i
    Just confirmed this worked on an E30 318is!! Thank you SO MUCH!!!!!!

  2. #27
    Join Date
    May 2012
    Location
    Bethesda
    Posts
    6
    My Cars
    91 535i
    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!

  3. #28
    Join Date
    Jul 2012
    Location
    exeter nh
    Posts
    24
    My Cars
    1991 BMW 850i
    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!!

  4. #29
    Join Date
    Sep 2017
    Location
    WY
    Posts
    18
    My Cars
    friend's 2003 525IT Wag
    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.

  5. #30
    Join Date
    Jan 2016
    Location
    Venice, CA
    Posts
    28
    My Cars
    1991 850i
    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

  6. #31
    Join Date
    Oct 2016
    Location
    Upper Darby, PA
    Posts
    12
    My Cars
    92 BMW 525i, 91 BMW 318i
    Just worked on a 92 525i. Thank you Legoman

  7. #32
    Join Date
    Jan 2016
    Location
    Venice, CA
    Posts
    28
    My Cars
    1991 850i
    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

  8. #33
    Join Date
    May 2008
    Location
    Campo, CA
    Posts
    68
    My Cars
    525i, K12RS, 07 750Li
    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

  9. #34
    Join Date
    Jul 2009
    Location
    Del Mar, CA
    Posts
    856
    My Cars
    91 850i, 01 740i, 06 760
    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
    Attached Images Attached Images

  10. #35
    Join Date
    May 2020
    Location
    Poland
    Posts
    206
    My Cars
    E32 1989 730iA M30
    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.

  11. #36
    Join Date
    Feb 2018
    Location
    Belmont, NC
    Posts
    55
    My Cars
    1988 BMW 735i
    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.

Page 2 of 2 FirstFirst 12

Similar Threads

  1. HOW TO: Reset Early Airbag/SRS light. No Special Tools!!!
    By legoman67 in forum 8 Series (E31)
    Replies: 54
    Last Post: 05-29-2023, 04:27 PM
  2. Airbag /SRS Light/Service/Oil Reset Tool - sold
    By shogun in forum 1988 - 1994 (E32)
    Replies: 14
    Last Post: 04-28-2016, 01:39 AM
  3. Replies: 4
    Last Post: 11-15-2008, 05:48 PM
  4. Anyone in SF have a tool that I can borrow to reset Airbag/SRS light?
    By xqwizit in forum California sponsored by Avus Autosport
    Replies: 0
    Last Post: 10-25-2008, 06:40 PM
  5. WTB: airbag / SRS light reset tool
    By John H in forum BMW Parts Wanted
    Replies: 0
    Last Post: 12-05-2003, 07:41 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •