My air bag light came on and I replaced the clock spring. The computer was reset with the current porsche tool. After a few months the light came on and it was reset with the porsche tool once more. The light has come on once again and cannot be reset...my mechanic is telling me I need to replace the air bag. Car has 25k miles and as far as can be told has not been involved in an accident however, it appears the (from the mechanic) someone has worked on the air bag componets before. He also states it is ok to drive with light on. Time for a new airbag? Should I buy a new one from a dealer or is it ok to buy a second hand one? Thanks for any input.

 

Tough call, because you don't actually know what's wrong with your system. It could be a loose wire, or could be your airbag ecu, or even the passenger airbag. Who knows. Installing new parts until the problem goes away is typically a very expensive solution.

It doesn't sound like you have any basis to suspect you need a new airbag, but in case you're going to diagnose it by simply replacing parts, I'd definitely get a used one. Just remember that 1995 airbags are not interchangeable with 1996-1998 since the frame is different.

 

I would ask your shop swap your airbag with one from another '95 to test the idea before shelling out for a new one. Not as easy to do the same with the passenger airbag or controller.

 

Thanks gents. I forgot to mention it's a '97 but I will ask him to swap components from another car and chase down potential culprits before blindly purchasing new units.

 

Check your seat sensors!

yea, diagnose the system, don't throw parts at it!

 

I didn't know there were seat sensors. I thought the current porsche testing tool/software was more accurate in finding the bad component. It seems like my trusty mechanic wants to replace everything without finding the root cause. I remember the first time the light came on, he just unplugged the old clock spring and cleaned it then reset it with the tool and it was good for awhile. Thanks for the comments and suggestions.

 

I still want to know about your avitar.....

 

Barney,

I took that picture with my blackberry. It was a young lady from rio that found my lap and gut comfortable for a little nap. One of those lucky moments that had to be photographed. Nothing happened that night but she was good company the next few days!

 

Isn't there a "freshness date" on all of our airbags? To be replaced like every ten years? I don't know many who adhere to that practice.

 

Your killing me..... Nice !!
Ok I'm done...

 

It should be possible for your tech to give a firm diagnosis on the airbag module. You can replace the airbag with an appropriate resistor. If the fault goes away that confirms that it is the airbag rather than any of the circuitry in between. I would certainly want this test done before paying for a new airbag. If your tech can't do this take it to a properly equipped shop.

pp

 

Yes the official guidance is ten years. This is due to the potential degradation of the airbag pyrotechnic constituents. However, the ten year life was established with some severe over testing. As an example a typical test program would require the car to experience temps of -40degC at night and +100degC in the daytime for a protracted period of time. In reality no car ever experiences that.

I'm a Degreed Engineer that spent many years working on airbag systems. I have had several cars with airbags over ten years old. I have never had the slightest concern about them having degraded.

pp

 

No, there are no seat sensors.

 

OBD1 should be able to diagnose whether its the bag itself or the module. Either way, I think this is a dealer-only fix. I've tried...