Airbag Faults - 7.9 Ohms on all lanes?

[benkay]

Hi All,

I've got an issue with an airbag + Service light showing.

I have Clip and have connected it to analyse the airbag ECU.

I have multiple errors that won't clear :

Code 74 - front airbag circuit 2, passenger open circuit
Code 65 - front seat position sensor circuit, driver short to ground
Code 75 - front airbag circuit 1, passenger open circuit
Code 71 - front airbag circuit 2, driver open circuit
Code 1 - ecu internal error

If I look into the ECU data, all lanes are reading 7.9 Ohms. (with the exception of the 2 rear curtain airbag lanes which show 0 Ohms, as they are not equipped on my car, it's a V6)

Of course the last fault makes me think of the ECU, but I also talked to a Renault master tech who said that's quite unlikely.

What I can't understand is what else could cause the various faults, across all the airbags and pre-tensioners...the wiring, as far as I can see is in perfect condition. I'm guessing it must be a common ground, or similar, to cause such high resistance readings on all lanes....but can somebody point me in a sensible direction as to where to look?

Thanks, Ben

 

[VenomUK]

Interested to see what people have to say on this matter as I've been playing with resistors for over a year now trying to get my lights to go out.

 

[benkay]

Hi All,

I've got an issue with an airbag + Service light showing.

I have Clip and have connected it to analyse the airbag ECU.

I have multiple errors that won't clear :

Code 74 - front airbag circuit 2, passenger open circuit
Code 65 - front seat position sensor circuit, driver short to ground
Code 75 - front airbag circuit 1, passenger open circuit
Code 71 - front airbag circuit 2, driver open circuit
Code 1 - ecu internal error

If I look into the ECU data, all lanes are reading 7.9 Ohms. (with the exception of the 2 rear curtain airbag lanes which show 0 Ohms, as they are not equipped on my car, it's a V6)

Of course the last fault makes me think of the ECU, but I also talked to a Renault master tech who said that's quite unlikely.

What I can't understand is what else could cause the various faults, across all the airbags and pre-tensioners...the wiring, as far as I can see is in perfect condition. I'm guessing it must be a common ground, or similar, to cause such high resistance readings on all lanes....but can somebody point me in a sensible direction as to where to look?

Thanks, Ben

So for anyone looking in the future. In my specific case it turned out to be the Airbag ECU. No idea why, no sign of anything on the unit itself. Perhaps a dry solder joint or something?

Replacing the Airbag ECU and programming it in to suit fixed the issue and airbag lines show sensible resistance readings again.