A5 3.0TDI Major Fault

[dsw88]

Can anyone help me with the fault I've got with my car, I've been without the car for around 7 weeks now due to not being able to source the fault.

The faults happened as I slowed down for a roundabout at the end of a dual carriage way in heavy rain.

The auto electrician has tried a ABS pump & module, can gateway and a body control module and it's still showing the ABS module cannot be contacted in VCDS.
He's also tried wiring the ABS pump/module direct and that hasn't worked. All the wiring has the correct readings when checked so no broken wires. Also there's no sign of water damage.

Here's a video of the faults please watch until the end.
https://drive.google.com/file/d/1qPwK22LagkZaGHj7SeQDQyzccJhjDsBr/view?usp=drivesdk

 

[Meemo]

wow thats allot of errors. I did have similar after driving in torrential rain, abs malfunction, followed by parking brake malfunction all over my screen and scanned lots of random abs module errors and a speed sensor error. I got a new wheel speed sensor, cleared the faults, scanned a few weeks later and bunch of ABS module faults was still up, replaced the car battery (your meant to recode the battery in via vag com as it stops modules working properly when its shuts down near end of life and needs to be tolds it can use the modules fully again).
Errors cleared and it never came back, but I really couldnt say if this is the same for yours.
Just to add, my car started perfect everytime and had no low battery warnings.

 

[RAF_S7]

I’ve seen similar Christmas tree lights effect on cars with a bad battery, or a dodgy earth connection between battery/chassis/engine, but not specifically on the A5 platform.

Would be worth checking at this point though.

 

[Jps3290]

Definitely worth trying a new battery. I was getting weird errors and had battery tested which apparently was ok. Changed it anyway (stop start) and problems went.

 

[desertstorm]

Very strange that the tacho keeps dropping to zero every now and then. I take it that wasn't happening before. Looks to me like you have issues not only communicating with the modules but the modules talking to each other. The cluster gets the engine speed from the ECU via the CAN bus. Have you checked the ECU out to make sure there is no water in there. The ECU is located under a cover on the drivers side at the back of the engine compartment. As stated earlier check the battery voltage is stable and the alternator is working correctly.
You may want to consider taking the car to a specialist. You could spend a lot of money changing out modules.

 

[dsw88]

Thanks for the replies. I'm back in the UK now so hopefully this week I can do some checks myself and have a dig around then post any updates.

 

[dsw88]

Abit of an update:

Took the car to a different garage after trying different things myself to no joy.

The garage is a German car specialists so hopefully get to the bottom of it, they've said from visually checking fuses and running diagnostics everything is pointing to the ABS pump so it's getting stripped off and sent away for testing tomorrow and then go from there.

 

[dsw88]

The car is finally fixed by the second garage I went to, it turns out it was corroded wiring in the front wing that was the problem but I'm ****** off because the first place I went said they'd checked there!!!!!

I'm over the moon that I've got my car back and couldn't recommend German Car Specialists in Doncaster more I know I'll be taking any work back to them in future.

 

[bobby singh]

The car is finally fixed by the second garage I went to, it turns out it was corroded wiring in the front wing that was the problem but I'm ****** off because the first place I went said they'd checked there!!!!!

I'm over the moon that I've got my car back and couldn't recommend German Car Specialists in Doncaster more I know I'll be taking any work back to them in future.

Excellent news- thanks for the update.
You have picture of the loom or which wiring it was?
Cheers

 

[dsw88]

This is the picture the garage took whilst doing the repair.
https://drive.google.com/file/d/1Hq7DKAQgsInkHWHjzcVrKSh7HYdFwSGK/view?usp=drivesdk

It might be worth people checking their wiring loom to avoid this problem, because with the arch liners being absorbent and the wiring loom resting on the top of it, that's how the corrosion is happening.

 

[Meemo]

amazing, hopefully if any one else gets the same they will see this glad they fixed it, decent diagnstic garages are hard to find, prob keep them on!