Aviator912

Hi all,

I am new to this group and really need some help with my Air Bag light. (sorry for long post)

The car is a 2001 986 S. I have had it for a few years with no airbag problems and recently took it to a body shop for some work. It was with them for a while and the battery went flat. When I took it back the air Bag light was on. The Body shop checked it with a tester and advised there was something wrong with the seat belt buckle. I had a few issues with them over other damage while it was with them so decided to take it back and solve the problem myself.

I have bought a Durameteric (also because I want to activate the OBC) and it tells me three Faults, No 3 (Low Voltage) 100 and 195.

In checking the seats, the passenger seat does not have a cable from the buckle to the connector under the seat, is this normal? ( The car has four airbags) The clips into which the cable fits are dusty and appear as though there was never any cable inserted, but the Porsche replacement buckle has a cable as standard??

Also in searching forums it appears there can be problems with the seat wiring and earthing issues with the connectors, but I can't see where these might be, especially as the passenger buckle has no wires attached.

So I wondered if anyone can tell me:

Do some cars not have the cable from the passenger seat to the connector under the seat?

If I replace the buckle should I attach the cable even though there never appears to have been one?

Where is wiring harness and earth connections that can cause problems?

What is the fault code explanation for 100 and 195.

Could the Fault code 3 be due to connector corrosion on the Airbag ECU?

Should I just replace the ECU with a matching Ebay one?

Many thanks in advance for any help

Macster

My reference offers:

Fault 3 -- Possible cause: Low battery positive voltage. Can be triggered when the battery disconnected or goes low and is recharged.

Fault 195 -- Fault codes above 100: Possible cause: Air bag triggering unit faulty.

Before you do any further be sure the battery is in good condition and when the engine is running the alternator is supplying sufficient voltage.

Before you start the engine check battery connections. At the battery but also where the battery leads eventually go and connect.

Start the engine and check battery power with a quality digital volt meter. Check the voltage with the engine running and then with the engine off. With the engine off the battery wants to show a 12.7 volt reading.

My info is:
Volts Charge
12.70 = 100%
12.50 = 90%
12.42 = 80%
12.32 = 70%
12.20 = 60%

While in some way a "bad" seat belt buckle or seat belt connection can trigger an error code seat belt buckle/seat belt errors/problems have their own error codes.

The seat belts have a pre-tensioner located in the shoulder strap portion. This pre-tensioner is controlled by the air bag control module. The seat belt buckle plays a role in the pre-tensioner's circuit in some fashion but I don't know the details.

(When the air bag light on my Boxster came on and there were no error codes the tech checked the seat belt buckles and the seat belts where they bolted to the sheet metal. The driver's side belt buckle release releases the buckle just fine but the red button stays down and the seat belt warning light doesn't come on. The tech did some kind of check -- used another belt buckle? -- and this didn't affect the light.)

In some MYs there are TSBs regarding the seat belts/buckles but I have no details on the TSBs. But like I said above none of the error codes are seat belt related.

I'm no air bag expert but a possible course of action could be after verifying the power is good to clear the codes assuming they can be cleared and there is nothing in the Porsche factory air bag service manual prohibitting this and then road testing the car.

If the warning light remains on for longer than a few seconds ( the air bag controller leaves the light on as it runs a system check which can take several seconds ) after key on or comes on at any time after engine start and going off then read the codes and go from there.

I am not familiar with Durametric and do not know if it can clear air bag errors.

If the some or all of the codes come back then based on what the factory reference has to say on the subject do that. 'course, you do not have access to the factory service manuals.

You may want to consider taking the car to a professional with the proper diagnostic computer and knowledge to properly trouble shoot this.

The air bag controller may be bad but you want a high confidence diagnosis of this. I don't know what a new air bag controller costs but my WAG is the cost is not insignificant.

As for the possibility of using a used air bag controller: I do know from my experience with an air bag warning light in my Boxster a new air bag controller has to be "introduced" to the car and this in some fashion ties the controller to the car. Whether this introduction can be undone and redone with another car to allow the use/function of the air bag controller in another car I have no idea.

Aviator912

Thanks for help,

battery is new and voltage good, I'm a bit stuck really, not sure what to try next...might just get a second hand Airbag Ecu and see if makes any difference. There was some commentary about the nuts that hold the Ecu to the chassis being hard to remove, does anybody have any idea about these?

tks