Adrian

The air bag as you know is a compressed explosive device. The actual internals of the air bag have a measurable resistance. If the air bag starts to expand caused by a leakage of chemicals forming a gas the resistance will increase as the bag expands.
When this resistance normally 4 or 5 ohms (can be checked with a proper low ohm meter) reaches a level which is too high the air bag control unit will pop up the warning light in the clock.
The air bag warning system is independent of the DME and of the central warning control unit (central informer).
The air bags may be expanded to far and with a resistance which is too high making the control unit think they have been deployed.
The special tool is Porsche number 9541.
I cover the air bags in my 964 book in a three chapters, 8, 9 and 10. However I do not go into great depth because the air bag system requires a trained mechanic.
One last thing is that maybe the crash sensor connectors have completed corroded away and this may be read by the control unit as being activated ie; registered a crash. You can check these yourself very easily. Just follow the wiring up towards the central electric to find the connectors.
Ciao,
Adrian.

PS: NEVER EVER use a mulitmeter which uses 9V power to check resistance on the air bag pill. The 9V could be enough to detonate the pill. Always use a low ohm meter setting on meters such as the Fluke 79 or 87. Always disconnect the battery and wait 20 minutes before working on the air bag system. This ensures all those pesky little capacitors in control units have discharged.

apeper

So I had the code read and this time I wrote word for word
HAMMER SCREEN READ AS BELOW
__________________________________________________________________
62
INGITION CURRENT CORRECT
( AFTER COLLISION)
__________________________________________________________________
IT WILL NOT RE-SET I EXPECT IT IS FAILED
ANYBODY KNOW WHATS WRONG WHEN IT SAYS THIS ?

Never wrecked allways pampered Air Bags not deployed
Apeper