logray

A working computer or another alarm module.

If you have a workshop manual it details all of the various points around the car to check using a multimeter, as well as a special tool (yes another special tool) might be required.

I would mirror what was said previously though, did you double check your re-install job on the steering wheel?

996 cab

Did you check if you have gas

dcdrechsel

Suggest you try and connect with Pedro Bonilla -www.pedrosgarage.com .He is very knowledgeable and I believe he had a similiar issue with his Boxster .
Dave

rkellison

OK, I have part of the mystery solved or at least narrowed down. It appears that the problem lies in the AirBag module. If I put a meter on the "Crash" output of the AB module I can see it start out at 12V as it goes through the self check. When it completes it, the voltage drops to 2.5v and the AB light comes on. If I open that circuit up(cut the wire) and apply a 12v signal to it, the engine cranks and runs OK. It is as if the AB module thiks that the car had been in a crash and has disabled the fuel flow. The question now is what portion of the AB circuitry has a problem and is telling it that a crash has occurred. From looking at the schematic, the parts monitored are seat belt buckles, child switch, driver airbag, passenger air bag and both side air bags. I know that the buckles and child switch will not cause a crash signal. I need to know how to test the air bags themselves. I assume that they have a resistance measurement and that once they are deployed that resistance is no longer there. If I put a Ohm meter across the airbag, will it deploy? Anyone out there an "expert" on SRS Airbags?

rkellison

I have more information on the AB system. It appears that the special tool that Porsche has for testing the wiring is a 3.9 Ohm resistor. This emulates an airbag and I can check the resistance of the wiring, clockspring, etc.. When I get a few minutes, I will check these out and report back.

rkellison

OK, I pulled the Drivers ABag and put in the load resistor. I should have seen 4 Ohms but all I got was 1.2. I suspect that I have either a wire pinched or a bad clockspring in the steering column. When I get a few minutes, I will disconnect it and make another measurement.

Dharn55

I have an extra clock spring if that turns out to be the problem.

logray

This info may or may not be useful for you as well...

rkellison

Thanks Dave, I may take you up on that.

Logray: I have not gotten to the reset point yet but since it has had only 1 false activation, I hope a replacement unit is not the case.

rkellison

Had a few minutes to do some more checking. I disconnected the clockspring and still get the low resistance reading. It looks like the problem is in the wiring. I have a USB snake camera that I am going to use to probe under the dash. Wish me luck.

Ericginpa

Geez this kinda thing scares the he'll outta me!

dcdrechsel

Good luck !Not so sure that the unit has only seen one false activation .Logic would indicate that every time the key is turned it starts a new duty cycle .If that is true you are well north of the max .There may be two issues -potential short and unit is full .Just food for thought......
Dave

logray

Or perhaps the continuity is fine, and it is actually the airbag module after all...

logray

Any updates?

Pac996

First thing I would check is wiring off the alternator being solid and correct. Just thinking maybe an improperly wired alternator started the ball rolling since an increase of rpms makes for a solid output from the alternator which would screw things around for sure. Just thinking maybe

I'd want to know why the gear picked parade time for falling on it tail.