Can you trust the result from OBD exam?

[Fiona&Johna]

Hi

Amber airbag fault warning light suddenly came on after getting van back from garage. We took it back and he diagnosed the fault was the clock spring. Can I be sure this is indeed a correct diagnosis? Is it possible it may just be a fuse or a dislodged wire, or would the OBD detect if that was the case.

 

[dspuk]

Modern vans are covered in sensors to aid diagnosis. If a specific sensor or part is monitored and gone, yes. I think random fuse and dislodged wire issues are (generally) left in the 90s.

 

[Roger Boeken]

typical when wire from airbag gets dislodged by turning front seat , only garage can reset this warning even if you reconnect the wires. This can happen if you try to store too much stuff under the seat. I speak from experience. In the T6 model there is quite some space under the seat and very tempting to fill it up. There have been threads about on this forum .

 

[secret lemonade drinker]

The clock spring is the circular cabling inside the steering wheel that allows the steering wheel controls and the airbag to be electrically connected when the steering wheel goes from full lock to full lock. So if it is the clock spring, simplistically it is a dislodged wire although typically the clock spring is now a flexible printed circuit board, did the garage do any work on the steering wheel before the fault occurred?

 

[Brian S]

There can be a break in the strip inside the clock spring casing.
This can be intermittent. It can be checked. You would need to disconnect the cable plug to the clock spring and test all the circuits using a audible continuity tester.
Test each circuit by turning the steering wheel fully left and right. Quite often the circuit will make and break at the steering position where the fault is located.

 

[vbk1975]

Hi

Amber airbag fault warning light suddenly came on after getting van back from garage. We took it back and he diagnosed the fault was the clock spring. Can I be sure this is indeed a correct diagnosis? Is it possible it may just be a fuse or a dislodged wire, or would the OBD detect if that was the case.

So the Airbag ECU has very comprehensive diagnostics, both from a hardware and software prospective.

The Airbag ECU will not be able to determine specifically it is the clock spring that is the issue, it will absolutely be able to determine that there is an issue in the circuit that goes through the clock-spring.

The circuit is two wires and there are no fuses involved and each Airbag circuit only connects to one airbag so the fault code will directly point an issue with the driver airbag circuit that goes through the clock spring.

I think it absolutely creditable and reasonable for the dealer to conclude the clock spring given history of issues (as a number of people have mentioned above) and the fact the rest of the wiring is static. The dealer have probably cleared the fault codes, rotated the steering wheel and created the issue again.

It is also possible that the dealer have fault codes that relate to other features that go through the clock spring that might be blind to the customer, but they have recorded an intermittent issue on the steering wheel switches etc. But the Airbag diagnostics is far more sensitive so it might be it just shows up as an airbag fault only.

A

 

[Phil Dub]

Hi

Amber airbag fault warning light suddenly came on after getting van back from garage. We took it back and he diagnosed the fault was the clock spring. Can I be sure this is indeed a correct diagnosis? Is it possible it may just be a fuse or a dislodged wire, or would the OBD detect if that was the case.

What was the camper in the garage for originally. It may be that the garage had caused the fault.
If you are lucky the fault may be a looseor dirty connection.

 

[WelshGas]

Hi

Amber airbag fault warning light suddenly came on after getting van back from garage. We took it back and he diagnosed the fault was the clock spring. Can I be sure this is indeed a correct diagnosis? Is it possible it may just be a fuse or a dislodged wire, or would the OBD detect if that was the case.

Any further news?

 

[Ch1pbutty]

There is a recall for some airbags at the moment - 2005/2018, so worth getting this checked as well:

Airbag safety recall campaign | Volkswagen UK

The global recall campaigns caused by a risk of fatal injury resulting from defective Takata airbags also affect Volkswagen models.

www.volkswagen.co.uk