Air Bag Malfunction
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From: Oakland, MI
This, to me, sounds more like an intermittent signal disconnect to the instrument cluster rather than the crash sensor connector problems, the tip-off being that the fault isn't stored and that the condition clears right away.
Looking at the Instrument Cluster electrical diagram for the '90 S4, I see that the air bag fault signal passes to the instrument cluster on plug 3 pin 11 (GN/YE wire from pin 6 of connector T52 for the air bag control unit; see upper-right hand part of Air Bag etc. diagram for the '90 S4). It might be worth reseating and DeoxIT-ing those connections.
Looking at the Instrument Cluster electrical diagram for the '90 S4, I see that the air bag fault signal passes to the instrument cluster on plug 3 pin 11 (GN/YE wire from pin 6 of connector T52 for the air bag control unit; see upper-right hand part of Air Bag etc. diagram for the '90 S4). It might be worth reseating and DeoxIT-ing those connections.
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From: Aurora, Ontario, Canada
Hi All,
Well, it's been three years with no air bag warnings, and after a meeting with a pothole, it's lit back up. Last time around I cleaned the passenger side connector to clear the error, it's probably time to do the driver's side. Had my head in there this morning, and even with Ed's picture, I'm just not finding the sensor or connector. Is there stuff I've got to remove to get this done?? Better yet, is there a picture from a little further back showing the exact location in relation to say the hood release, door wiirng, or some other reference point? I don't fit well in there so anything to speed it up will help!
TIA!
Well, it's been three years with no air bag warnings, and after a meeting with a pothole, it's lit back up. Last time around I cleaned the passenger side connector to clear the error, it's probably time to do the driver's side. Had my head in there this morning, and even with Ed's picture, I'm just not finding the sensor or connector. Is there stuff I've got to remove to get this done?? Better yet, is there a picture from a little further back showing the exact location in relation to say the hood release, door wiirng, or some other reference point? I don't fit well in there so anything to speed it up will help!
TIA!
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From: Y-Bridge City, Zanesville, Ohio
Ed, Thanks. Here's a public ATTABOY for all the links. Way to go! I love useful posts, I say as I post one that isn't. (unless it encourages others to load their posts with linx)
Will
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From: Rep of Texas, N NM, Rockies, SoCal
The drivers side connector is in the same place on the car as the pax side, up at the apex of the A pillar and dash extrusion. You do have to remove the module that is mounted below it on the sidewall, I think it's the RDK module. Once that is out, you can lay on your back on the drivers seat, with your head under the wheel and possibly see it. It's a black connector, and it should be in a small body color clip holding it against the sidewall. Sometimes you also need to loosen the duct that feeds the drivers door from under the dash, and push it in and out of the way. Use a good penlight and you should be able to find it.
You also should clean the main connector on the ABS module. It requires a special tool for the anti-tamper bolts, but I just used a dremel to put a slot in the head, and take it out with a regular driver.
You also should clean the main connector on the ABS module. It requires a special tool for the anti-tamper bolts, but I just used a dremel to put a slot in the head, and take it out with a regular driver.
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From: Aurora, Ontario, Canada
Thanks!
The drivers side connector is in the same place on the car as the pax side, up at the apex of the A pillar and dash extrusion. You do have to remove the module that is mounted below it on the sidewall, I think it's the RDK module. Once that is out, you can lay on your back on the drivers seat, with your head under the wheel and possibly see it. It's a black connector, and it should be in a small body color clip holding it against the sidewall. Sometimes you also need to loosen the duct that feeds the drivers door from under the dash, and push it in and out of the way. Use a good penlight and you should be able to find it.
You also should clean the main connector on the ABS module. It requires a special tool for the anti-tamper bolts, but I just used a dremel to put a slot in the head, and take it out with a regular driver.
You also should clean the main connector on the ABS module. It requires a special tool for the anti-tamper bolts, but I just used a dremel to put a slot in the head, and take it out with a regular driver.
I figured something had to get removed.......and I didn't want to just go in without some insight. I'll report back in a few days. Back to the office tomorrow....
1st Gear
Joined: Oct 2012
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AIRBAG MALFUNCTION
I have an "airbag malfunction" warning on my 90 928 s4. I have a DURAMETRIC scanner with a couple of codes (21) and (112). According to this I have Fault code 19 indicates "Contact resistance against ground of left front sensor." Any fault code above 100 is an unknown fault code. For these, Porsche recommends checking the secondary ignition circuit and erasing fault memory.
I've replaced the airbag clock spring and cleaned the left side crash sensor. I even connected another sensor to the harness (left side)...erased the error codes with my durametric and still the codes
I've replaced the airbag clock spring and cleaned the left side crash sensor. I even connected another sensor to the harness (left side)...erased the error codes with my durametric and still the codes
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From: Rep of Texas, N NM, Rockies, SoCal
No. The airbag wiring is independent of all other systems. It is either the high resistance on one of the sensors, or the clockspring intermittant, or out of whack.
2nd Gear
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I figured that its an independent system, but the seatbelt warning light stays on followed by the airbag light. I noticed that when the fault got corrected the seatbelt light would turn off.
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From: Rep of Texas, N NM, Rockies, SoCal
This is normal behavior on several years. Setting the seat belt warning light is a safety feature. The airbag warning will pull up the seat belt lamp as well. Once the airbag system is fixed, the seat belt warning will operate as a warning only for the belt.
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Bill resolved this issue on my car. He removed the pod with steering wheel in place. We replaced some bulbs in the cluster, and re-installed. Since we could not fully test the cluster lights and gauges outside of the car, we turned on the ignition to verify. This triggered an airbag warning as soon as the engine was started.
Bill used Theo's tool to read the code, which pointed to a cluster connection. He cleared the code. The warning has not come-back since.
Bill used Theo's tool to read the code, which pointed to a cluster connection. He cleared the code. The warning has not come-back since.
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From: Gatineau, Québec, Canada
This is exactly what is happening to my car...I hit a bump or expansion joint in the road and the both display and warning light comes on. Both clear by themselves after a few seconds if another bump doesn't come along. I also hear a clicking noise somewhere under the dash or behind the center console. Happens everytime I drive it so would love to get this one fixed.
Did you ever find out how to resolve this problem?
I have the same problem with my car - both display and warning light come on and leave after few seconds.
This looks like a bad connection to me. But no fault is stored (I think) as both the warning and display lights turn off after about 5 seconds.
- I cleaned (Deoxit) both crash sensor connections.
- Removed the airbag and steering wheel and clean all connections there.
- Removed the cluster and cleaned the four big connections. After reading Nicole's post here, I thought this could be the problem.
All this without any luck...
Any other suggestion?
Thank you.
Drifting
Joined: May 2010
Posts: 2,095
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From: Northern Virginia
If the 928 uses a "clock spring" type connector check it for continuity. If it fails, replace the clock spring. The clock spring is the ribbon connector. It has thin copper ribbon wires dedicated to anything functioning in the steering wheel (horn, Airbag, radio, cruise control). I fixed this exact problem by testing and replacing the clock spring in a 1990 Volvo. Years of winding the steering wheel back and forth, and thus winding the clock spring, causes chafing or fatigue in the thin wires. The break can be so small that contact remains until jiggled when driving over a bump or rough road.
How to test clock spring:
This detailed video is for a Lexus, but clock springs are pretty much a universal thing. Good video....especially cautions about how not to break the thin wires in the clock spring.
How to test clock spring:
This detailed video is for a Lexus, but clock springs are pretty much a universal thing. Good video....especially cautions about how not to break the thin wires in the clock spring.
Eric,
Did you ever find out how to resolve this problem?
I have the same problem with my car - both display and warning light come on and leave after few seconds.
This looks like a bad connection to me. But no fault is stored (I think) as both the warning and display lights turn off after about 5 seconds.
- I cleaned (Deoxit) both crash sensor connections.
- Removed the airbag and steering wheel and clean all connections there.
- Removed the cluster and cleaned the four big connections. After reading Nicole's post here, I thought this could be the problem.
All this without any luck...
Any other suggestion?
Thank you.
Did you ever find out how to resolve this problem?
I have the same problem with my car - both display and warning light come on and leave after few seconds.
This looks like a bad connection to me. But no fault is stored (I think) as both the warning and display lights turn off after about 5 seconds.
- I cleaned (Deoxit) both crash sensor connections.
- Removed the airbag and steering wheel and clean all connections there.
- Removed the cluster and cleaned the four big connections. After reading Nicole's post here, I thought this could be the problem.
All this without any luck...
Any other suggestion?
Thank you.
Last edited by Captain_Slow; Sep 5, 2016 at 02:48 PM.