The SRS light in my '89 comes on almost immediately after starting the car up. I had my indy try to reset it for me last week, and he couldn't. He seems to think that the SRS module is "fried".
Any ideas on how to diagnose this, and find out if in fact the module is shot?
SRS Module Help
Moderators: GRNSHRK, ron, bfons
on many cars the SRS module is checked for voltage at start-up. The SRS module contains a capacitor that will power the system for a split second should the power be disconnected during an accident. When the key is turned to II the capacitor is charged, and it is then checked for voltage on many systems.
Since the volts drop a lot when the starter cranks, if for some reason the capacitor isn't charged the test can be failed. Most often this happens if one cell is going bad in the battery.
On one car I had I could reset the fault codes (which were multiple and read total system failure BTW) and they would return; but if I left the ignition on II for a few seconds before cranking it it never came back.
A new battery sorted it out completely.
The 6er system may have a similar characteristic, worth a look, I'd say.
cheers
Since the volts drop a lot when the starter cranks, if for some reason the capacitor isn't charged the test can be failed. Most often this happens if one cell is going bad in the battery.
On one car I had I could reset the fault codes (which were multiple and read total system failure BTW) and they would return; but if I left the ignition on II for a few seconds before cranking it it never came back.
A new battery sorted it out completely.
The 6er system may have a similar characteristic, worth a look, I'd say.
cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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The Sixer Kid
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samer0214
Thanks Brucey,
My battery is fine, so I don't think this is the issue. My indie said he could not "get into" the SRS module to even read any faults, and that's why he suspects that the module needs to be replaced.
Does this sound right? What would cause a module to go bad, and hoe to actually test it?
My battery is fine, so I don't think this is the issue. My indie said he could not "get into" the SRS module to even read any faults, and that's why he suspects that the module needs to be replaced.
Does this sound right? What would cause a module to go bad, and hoe to actually test it?
BMW will have a test procedure for this; I'll check a manual I have to see if there is anything that can be done without the 'gizmo' for it.
It may be that the easiest test for you is that old favourite 'known good substitution'. This can get expensive if you have to buy the bits though....
Do bear in mind that a bad connection (in say, the bottom of the fuse box, a notorious spot) could cause the 'bad battery' symptoms too; best check the 12 volts are holding up at the unit itself before assuming all is well with the live feed; same goes for the ground connections too.
sorry I can't be of more help
cheers
It may be that the easiest test for you is that old favourite 'known good substitution'. This can get expensive if you have to buy the bits though....
Do bear in mind that a bad connection (in say, the bottom of the fuse box, a notorious spot) could cause the 'bad battery' symptoms too; best check the 12 volts are holding up at the unit itself before assuming all is well with the live feed; same goes for the ground connections too.
sorry I can't be of more help
cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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Tommys 89 635
- Posts: 523
- Joined: Mon Oct 30, 2006 8:23 pm
- Location: San Mateo, CA just South of San Francisco
About a year ago, the D light went out on my conductor plate which is located behind the instrument cluster so I thought I would save some money on a few hours labor and change it myself. Everything went well and I felt good about the job but low and behold the SRS light was on and I retraced my steps and everything looked good. I spoke to a few people and told them what I did and they said that the airbag sensor was disturbed. A friend of mine tired to reset it and no dice. I dropped off my car at my mechanic, I gave them all the details on what I did and they spent some time retracing what I did and everything looked ok. They were able to reset it by jumping something. I forget how but at that point I was a bit bummed because I could had the conductor plate changed and saved some time and money on headaches.
Basically when you turn your key to the on position, the SRS scans the airbag system and makes sure everything works, ie: airbag, crash sensors, relays, blah blah blah...
I did have to lower the steering column maybe 2-3 inches to get to the conductor plate and that may have been enough to disrupt the SRS system.
You should probably go to a BMW specialty shop and let them take a look or as what Brucey said maybe go to the dealer and have them perform the test and save the headaches.
Sorry I forgot the fix.
As what Brucy said
Basically when you turn your key to the on position, the SRS scans the airbag system and makes sure everything works, ie: airbag, crash sensors, relays, blah blah blah...
I did have to lower the steering column maybe 2-3 inches to get to the conductor plate and that may have been enough to disrupt the SRS system.
You should probably go to a BMW specialty shop and let them take a look or as what Brucey said maybe go to the dealer and have them perform the test and save the headaches.
Sorry I forgot the fix.
As what Brucy said
Last edited by Tommys 89 635 on Mon Jun 13, 2022 7:49 pm, edited 1 time in total.
Tommy
1989 635 CSI (Second owner since Jun 1995, driven daily and retired in 2013 with 295k to occasional driving)
2011 335D (Daily driver) with 103,550
1989 635 CSI (Second owner since Jun 1995, driven daily and retired in 2013 with 295k to occasional driving)
2011 335D (Daily driver) with 103,550
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Tommys 89 635
- Posts: 523
- Joined: Mon Oct 30, 2006 8:23 pm
- Location: San Mateo, CA just South of San Francisco
About a year ago, the D light went out on my conductor plate which is located behind the instrument cluster so I thought I would save some money on a few hours labor and change it myself. Everything went well and I felt good about the job but low and behold the SRS light was on and I retraced my steps and everything looked good. I spoke to a few people and told them what I did and they said that the airbag sensor was disturbed. A friend of mine tired to reset it and no dice. I dropped off my car at my mechanic, I gave them all the details on what I did and they spent some time retracing what I did and everything looked ok. They were able to reset it by jumping something. I forget how but at that point I was a bit bummed because I could had the conductor plate changed and saved some time and money on headaches.
Basically when you turn your key to the on position, the SRS scans the airbag system and makes sure everything works, ie: airbag, crash sensors, relays, blah blah blah...
I did have to lower the steering column maybe 2-3 inches to get to the conductor plate and that may have been enough to disrupt the SRS system.
You should probably go to a BMW specialty shop and let them take a look or as what Brucey said maybe go to the dealer and have them perform the test and save the headaches.
Sorry I forgot the fix.
As what Brucy said
Basically when you turn your key to the on position, the SRS scans the airbag system and makes sure everything works, ie: airbag, crash sensors, relays, blah blah blah...
I did have to lower the steering column maybe 2-3 inches to get to the conductor plate and that may have been enough to disrupt the SRS system.
You should probably go to a BMW specialty shop and let them take a look or as what Brucey said maybe go to the dealer and have them perform the test and save the headaches.
Sorry I forgot the fix.
As what Brucy said
Last edited by Tommys 89 635 on Mon Jun 13, 2022 7:48 pm, edited 1 time in total.
Tommy
1989 635 CSI (Second owner since Jun 1995, driven daily and retired in 2013 with 295k to occasional driving)
2011 335D (Daily driver) with 103,550
1989 635 CSI (Second owner since Jun 1995, driven daily and retired in 2013 with 295k to occasional driving)
2011 335D (Daily driver) with 103,550
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clayjo
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clayjo
My retired ex-mechanic states that
" The SRS system wasn't hooked up to the diagnostic socket. Your mechanic needs to access the plug that powers the SRS module under the dash and follow the directions on a BMW service bulletin to clear the code. "
Does anybody have this procedure to clear late 6 model SRS airbag codes?
" The SRS system wasn't hooked up to the diagnostic socket. Your mechanic needs to access the plug that powers the SRS module under the dash and follow the directions on a BMW service bulletin to clear the code. "
Does anybody have this procedure to clear late 6 model SRS airbag codes?
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clayjo
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clayjo
turning off the SRS light
Does anybody have the BMW TIS discs?
OR can translate this for me?
"What I remember is that you connect the TXD, RXD, power and ground to the correct pins on the diagnostic plug of the scan tool and you can communicate with the airbag module. This has to be done right at the module plug so the lower dash panel has to be removed."
OR can translate this for me?
"What I remember is that you connect the TXD, RXD, power and ground to the correct pins on the diagnostic plug of the scan tool and you can communicate with the airbag module. This has to be done right at the module plug so the lower dash panel has to be removed."
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Chris Wright
Re: turning off the SRS light
I don't think we are ignoring you ..... just no information. I dug through the factory CD and found nothing as well as some Service Bulletin Micro fiche that I have, and again, nothing.clayjo wrote:Does anybody have the BMW TIS discs?
OR can translate this for me?
"What I remember is that you connect the TXD, RXD, power and ground to the correct pins on the diagnostic plug of the scan tool and you can communicate with the airbag module. This has to be done right at the module plug so the lower dash panel has to be removed."
I can tell you that TXD = Transmit Data line (or pin) and RXD = Receive Data line (or pin).
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Chris Wright
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Here is a link to the Factory diagnosis of the SRS:
http://www.normgrills.net/bcg/SRS.html
Here are some links to quick fixes of the SRS:
http://www.normgrills.net/bcg/Electrica ... hor2172359
http://www.normgrills.net/bcg/Steering_ ... -SRS-49575
Here is a link to the Factory diagnosis of the SRS:
http://www.normgrills.net/bcg/SRS.html
Here are some links to quick fixes of the SRS:
http://www.normgrills.net/bcg/Electrica ... hor2172359
http://www.normgrills.net/bcg/Steering_ ... -SRS-49575
Success...used the first quick fix which required disconnecting (a) negative on battery then (b) disconnecting the two orange connectors in engine compartment...then (c) disconnecting the 3 plugs under the right side of dash from the SRS control module.
Reconnected all the plugs and battery...cranked and SRS light did not remain on.
Thanks Chris
Reconnected all the plugs and battery...cranked and SRS light did not remain on.
Thanks Chris
88 635i
87 325iC
87 325iC
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FriendlyVolcano
- Posts: 10
- Joined: Fri Nov 22, 2019 10:29 pm
- Location: Portland Oregon
Re: SRS Module Help
I just did the same maneuver which also worked, except I only disconnected the orange connectors on the left and right fender sides.
The ancient plastic of the orange connectors were crumbling in my hands, so if you do it, make sure you have some electrical tape handy to hold them together after you put them back together.
The ancient plastic of the orange connectors were crumbling in my hands, so if you do it, make sure you have some electrical tape handy to hold them together after you put them back together.