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

[JamesM3M5]

Just confirmed this worked on an E30 318is!! Thank you SO MUCH!!

[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. Thanks for posting this!

[rick8637]

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!!

[honda.lioness]

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.

[Bsangerman]

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?

[cupitone]

Just worked on a 92 525i. Thank you Legoman

[Bsangerman]

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

[mnewman]

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

[Bsangerman]

Does anyone know if this process of reading the codes is the same process for the E31? Is the E30 have the same diagnostic connector as the 91 850i? Does the SRS light in the gauge cluster flash for codes?

[shogun]

The E30 has 2 kinds of diagnostic connectors depending on built year, D-Type with 15 pins up to around 1987, and then the 20-pin connector https://www.e30zone.net/e30wiki/inde...iagnostic_Plug

[Bsangerman]

Thanks Shogun. Looks like previous poster did this on a ‘92 so the 20pin connector. But the pin# layout in the link you provided is different than the one on page one of this thread that Timm posted. Is the layout vehicle specific. Either way, shorting Pins 1 and 6 don’t work on my car. On timm’s image, I have no #6, and on the e30 image in the link you provided I have no #1 pin.

[shogun]

If the pinout is slightly different and depends on year and model, has to be checked, check in the ETMs http://wedophones.com/BMWManualsLead.htm

[Bsangerman]

If the pinout is slightly different and depends on year and model, has to be checked, check in the ETMs http://wedophones.com/BMWManualsLead.htm

So helpful Shogun. Thank you

The options don’t match, so I wonder if there is another pin sequence that would do the same. The 92 325i used pin 1 and 6, 6 being “SRS connector”

Options:

92 325i cab
1 Ignition coil
6 SRS connector

91 850i
1 Ignition coil
7 Service interval reset
11 Voltage: ignition switch in start
12 Alternator change indicator
13 Speedometer signal output
14 Voltage: hot at all times
15 Diagnostic datalink
16 Voltage: ignition switch in run and switch
18 Program select for DME control unit
19 Ground
20 Diagnostic Datalink

[adrianz]

The procedure did not work on my '89 E32 735. UN-grounding pin 15 the first time puts the SRS light into diagnostic mode where I was able to pull the error codes by counting the flashes. I'm fairly confident that the errors are no longer valid since I know how I caused them and have since fixed the issue, but I'm stuck unable to clear them.

[shogun]

see how demetk made it with a switch https://www.bimmerforums.com/forum/s...3#post28926233
"This procedure actually worked on my 89. Tap into the white/yellow receive wire at the srs module. Maybe take a look at the ETM for your car and see if you can do anything with the white/violet wire at the srs module that is usually connected to pin 20 of the datalink connector. I'd be tempted to install a datalink connector and connect power, ground and the white/violet wire in the correct places. Maybe a reset tool will then work. On my 89 535 I was able to perform a manual reset of the srs light by switching the srs to ground a couple of times in a specially timed sequence that I found on the net. On my car the srs wire was connected to pin 15. " https://www.bimmerforums.com/forum/s...&highlight=srs

[Goat1180]

So, I've read a bunch of posts about this SRS light reset trick without tools and with Shogun's tool etc... I have a 1993 E34 M5 that I bought with a non airbag steering wheel. The SRS light had never been on until I screwed up while taking the cluster out without having disconnected the battery first. (I know, I'm a dumbass.) It's flashing now... Getting to the point: Will the jumper trick reset the light? I understand I'm not trying to trick the system, just to reset it to how it was when I bought it. I've no idea how it didn't flash with the non airbag wheel to begin with. Otherwise, can I disconnect the "big orange connector" under the dash with no ill effect?

[The Pondman]

Had blinking SRS light, removed steering wheel to straighten it out, whomever had it off previously installed it upside down. While doing this I found SRS plug inside column was disconnected so I plugged it back in. Now I'm doing this jumper wire reset procedure from pin #15 under the hood to pin #6 at SRS 8 pin plug under the glove box. Question is, what color wire is pin #6? TIA

[Omar.pellot]

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. wait five seconds
5. disconnect the jumper.
6. Wait another five seconds.
7. Reconnect the jumper
8. After five seconds
9. disconnect the jumpers.
10. Wait five seconds
11. Turn the ignition switch off.
12. 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.

Which pin is the correct? The 15 or the 14? In another forum is stated that there was an error on pi selection.

[Omar.pellot]

https://www.bimmerforums.com/forum/s...exx-SIR3-tool&

[BMSman]

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...

SRS_reset.jpg
SRS2.JPG

[zapass]

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.

[LappingLuke]

Just tried a few more times this time using a stop watch. Still no luck for me. Just been driving around with the warning light on...not sure what I'm screwing up. I'm all for free fixes but at this point can I pay for a tool to plug in and easy button this away?

I'm sure if I took it to the local BMW dealer they wouldn't even know what the car was and probably only know how to replace valve cover gaskets on N54 motors anyway.
For reference I also triggered the light by pulling my steering wheel to get the cluster out. I'm sure there's nothing actually wrong...

[LappingLuke]

Can "the Peak tool" do it? Can one even buy them anymore?

[04SSHD]

Can "the Peak tool" do it? Can one even buy them anymore?

I have a Peak tool, not sure if it can reset the SRS but I can try and report back. My SRS light is on and this timing reset did not work on my 11/93 production 1994 MY 840Ci

[shogun]

Peake Research R5/SRS Airbag SRS Scan/Reset Tool as well as the cheap SRS B800 Made in China work on newer BMW's from 1994-mid 2000, so probably not on E31, E32, E34. Different p/n of the module (?)
I tested the B800 tool on a 1993 E32, did not work, but it worked on my 1998/02 E36 M3, could read SRS fault codes and delete the fault (passenger seat occupancy sensor)