Airbag Light No Fault Codes Found

[Dan Hinkebein]

In my 2000 996 C2 while driving to work today I hit a bump and my airbag light came on. Assuming it was the typical seat belt ground issue, I plugged in my Durametric and went to the airbag fault codes. It shows a green check mark and no fault codes. I went ahead and selected reset codes anyway. The light went off for a few seconds then came right back on. I rescanned and still no codes. I turned the ignition off and all of the lights went out on the dash then the airbag light came back on. When I take the key out the airbag light goes off. When I put the key back in and turn the ignition on, the airbag light flashes off then stays on again even when the key is turned off. Any ideas?

[judgejon]

check connectors in buckles. clean contacts. replace with gold connectors? strange that Durametric doesn't clear. maybe try it several times. good luck

[JFP in PA]

In my 2000 996 C2 while driving to work today I hit a bump and my airbag light came on. Assuming it was the typical seat belt ground issue, I plugged in my Durametric and went to the airbag fault codes. It shows a green check mark and no fault codes. I went ahead and selected reset codes anyway. The light went off for a few seconds then came right back on. I rescanned and still no codes. I turned the ignition off and all of the lights went out on the dash then the airbag light came back on. When I take the key out the airbag light goes off. When I put the key back in and turn the ignition on, the airbag light flashes off then stays on again even when the key is turned off. Any ideas?

Check the car's electrical system for the correct voltage at idle; voltage fluctuations can lead to ghost MIL's on several systems. I would also play around with the ignition switch, the $15 electrical section of the switch is well known for causing all kinds of weird electrical faults as well.

[Dan Hinkebein]

Thank JFP. That's the way I was leaning also. I replaced the switch a few months ago but as you stated it's a known common problem and a cheap place to start.

[Dan Hinkebein]

Okay, after replacing the ignition switch airbag light was still on. I connected Durametric and it still showed the green dot with check mark and no codes. I went ahead and clicked reset and the Airbag light went off. Driving to work the next morning it came back on. Durametric still shows no fault codes. I took the car to my independent guy to replace the clutch and he used his system to check and found "code #4" in the airbag fault memory, "Short to Ground in Drivers airbag circuit" . According to ALLDATA you have to attach "test tool # 9516" in place of the drivers airbag in order to trace the short. What does this box do and can it be replicated? Or, will I need to go to the dealer to search for this short?

[JFP in PA]

The test tool is a "air bag simulator" used to test the bag circuits without causing the air bag to go off. OEM procedure is as follows:

1. Remove driver's airbag unit.
2. Attach the special tool 9516 instead of the airbag unit.
3. Clear the fault memory.
4. Check whether the fault appears again.
a If the fault does not appear again, replace the airbag unit.
b If the fault appears again, disconnect plug connection to the contact unit and attach special tool 9516/1.
5. Clear the fault memory.
6. Check whether the fault appears again.
a If the fault does not appear again, replace the contact unit.
b If the fault appears again, check the wiring harness for pinches and chafing damage.
c If no fault is found on the wiring harness, replace the triggering unit.

Proceed as described below to determine whether the fault was eliminated:
1. Clear the fault memory.
2. Switch oft ignition.
3. Remove ignition key.
4. Switch on ignition.

You may need to borrow the airbag tool (a special resister in box with the correct connector) or
find a shop that has one.

[Richard Hamilton]

The resistor value you need is 2.8 ohms, 0.25 watt to simulate the airbag. Anywhere between 2.8 and 2.9 ohms should work fine. That's the size most people use when fitting non-airbag steering wheels.

[Dan Hinkebein]

Thanks Richard, that is very helpful information.

[987_RDC]

Perhaps grab a seat belt receptical off eBay and swap it in. Clear code and see if it returns?

[Dan Hinkebein]

987_RDC, this code has nothing to do with the seatbelt issue. This code is for a hot lead shorting to ground with in the steering wheel airbag circuit. I have the test procedures from Alldata, I just needed to know how to duplicate the box the dealers plug in in place of the airbag so that I can go through the test procedures. That's the info Richard provided above.