Errore After disassembling and reassembling of front bumper

[teone123]

Hi everyone,


I'm writing here hoping to get some advice from you. I own an Audi A4 B9, and after a major service on my car, I've ended up with a series of really bizarre electrical problems.


What I did: I just had the timing belt replaced. For this job, the mechanic had to remove and then reinstall the front bumper.


The situation: About ten days later, a real "festival" of errors appeared. All of these messages popped up at the same time:

• Outside air temperature sensor no longer working
• TPMS (Tire Pressure Monitoring System) unavailable
• Parking sensors unavailable
• Adaptive Cruise Control unavailable
• Audi pre sense unavailable
• The climate control is in "protection" mode (it no longer blows cold air)

The battery is brand new and fully charged, so I would rule out any voltage issues.


My questions for you:

1. Is it possible that all these sensors and systems are connected to a single wiring loom or connector located behind the bumper? It seems like the only plausible explanation for such a massive wave of errors.
2. Do I need to perform the Adaptive Cruise Control (ACC) alignment procedure after the bumper has been removed? Is this a mandatory step? The mechanic didn't mention anything about it.
3. Has anyone had a similar experience? Do you have any advice on what to check first?

Any suggestion is welcome. Thanks in advance!

 

[NHN]

Solo inglese

 

[teone123]

Translated, sorry my mistake

 

[NHN]

Niente problemo, Grazie

 

[NHN]

Sounds to me like the wiring loom or fuse etc has been disturbed or damaged, check all round where the work was completed.

 

[teone123]

Fuses, under left foot rest pad, are all good. Double checked them yesterday and they are ok.
I suspect you are right... moreover, during normal driving, sometimes the errors disappear (it's rare, but it happened twice) to reappear after some minutes. Might be some connection, right?

Moreover, any experience with recalibrating ACC?
Is it something I should request from my mechanic (it's not Audi)?

Thanks

 

[NHN]

Honestly I'd say a loom has been damaged & it's sporadically getting a connection.

I know eg A7 the loom can get cut between the bumper & bump bar, I'd work backwards.

Also until all errors are gone don't calibrate the ACC as it may need doing again once the errors are cleared.

 

[teone123]

thanks! super helpful, I'm gonna suggest my mechanic to inspect that

 

[NHN]

Niente, amico.