Side airbags Open Circuit

[alstarz88]

Hi

 

I have a 2002 spec Porsche boxster S and I have my airbag light on  I took it to an independent geman car specialists to turn the light off as I suspected it was to do with some work I was doing on steering wheel however there appears to be codes for drivers and passengers airbags these are showing an open circuit and return once cleared.

 

I have checked all wires to the airbag ecu from side airbags and sensors for being grounded but no luck I find it a coincidence that both sides would go at the same time.

 

I have ordered a replacement ecu with correct number of airbags for my car to see if it is the ecu.

 

When checking the wiring for the airbags I noticed that the airbags circuits are bridged at the door connectors as well as in the connector for the ecu. Is this normal

 

There appears to be only the orange wire to the ecu that connects the two side airbag sensors together does anyone know what this does as this seems to be the only common link between both sides

 

Thanks for reading

 

 

[alstarz88]

fault codes are 31,28,24,22

[Loren]

Faults 28 and 31 -- Ignition circuit, side airbag

Fault 22 -- Driver's seat belt tensioner

Fault 24 -- Passenger's seat belt tensioner

 

Was the car involved in an accident? Did one or more airbags deploy?

If so, then the seat belt tensioners will have to be replaced.

[alstarz88]

Seat belts were from a brakers so its possible although i would hope they would know about that issue 

 

Is the ignition circuit the sensors near the door shuts if so I have tested the wire coming from them to the ecu (pin 20/21) and I am receiving 5.5V  which would lead me to believe it is getting power. 

[alstarz88]

Also replaced airbag ECU and get the same faults

[Loren]

You really need a Porsche diagnostic tool (PST2 or PIWIS) and a special Porsche airbag tester to safely and properly test airbag circuits.

The last thing you want to do it is trigger one or more airbags.

[alstarz88]

No airbags have been deployed the car has not been in an accident

Edited November 4, 2015 by alstarz88

[alstarz88]

ECU was disconnected whilst I was testing the voltage thought that would prevent airbags deploying

Edited November 4, 2015 by alstarz88

[Loren]

ECU was disconnected whilst I was testing the voltage thought that would prevent airbags deploying

 

No it will not.

I have seen an airbag removed from a car and the tech bumped it while removing another part and it fired off.

Please be very careful when testing or working on airbags.

 

As I said before without a Porsche diagnostic tool you are just guessing at the bad part.

[JFP in PA]

+1.  These units can be quite dangerous, even to those that work with them regularly.