Parking Aid Fault on 2015 Avant

[Jenno]

Hi Guys
My 2015 A6 C7 Avant rear parking sensors aren’t working (fronts are fine). I just get a flatline and a P with a cross through it on the display. Had the car scanned today and it says I have an open circuit on the rear system. None of the rears click if you put your ear to them so assume its probably wiring. Before bumper comes off I just wondered if any of the wiring or the control module can be accessed and checked in case its just a loose connection ? Any advice would be greatly received. Cheers.

 

[Stig414]

Check from the module to where it goes to the outside. I bet the ground wire broken in the loom

 

[Jenno]

Check from the module to where it goes to the outside. I bet the ground wire broken in the loom

Thanks for the advice. Any idea where the module is on a 2015 ?

 

[Stig414]

Right rear, near fuse box behind the panel you unlock with a quarter turn. It's clipped in one of the racks. Easier to look behind the panel where it comes into the car, roughly underneath the outer light but inline with the sensor area and follow to the module that way. Sounds complicated but straightforward when looking at it.

 

[Jenno]

Thanks Stig414 I've traced it into the car and into a plug but it then goes off into a loom that runs toward the front of the car. Not sure if i read somewhere that the module is combined with another module on 2015 and later. Or might it be behind the carpet forward of the fusebox panel ?

 

[Stig414]

The rears plug into the module nr fuse box, and a loom from the front sensors comes to the module, and finally a third loom goes to the car for power and can wires etc. Box is very roughly 100mm square and 30mm thick, and will be pushed and clicked into the rack behind the suspension/fuel filler area

 

[Jenno]

Looked everywhere in there and can’t see it. Having done a bit of research I think it was combined into the comfort control module on the 2015 facelift. Whatever that is. The only box in the fuse area is a parking brake module.

 

[Stig414]

Mine is a facelift and it is definitely in there. Depending what time I finish work tonight, I'll send you a pic. I'm surprised you can't find it

 

[Jenno]

Very strange. Definitely cant see it in there anywhere. Fronts still work so there must be one somewhere.
I did take a video but cant seem to be able to upload it.

 

[Jenno]

Mine is a facelift and it is definitely in there. Depending what time I finish work tonight, I'll send you a pic. I'm surprised you can't find it

Heres a video.

Vimeo

vimeo.com

 

[Stig414]

This is my setup in the rear of my face lift Allroad

 

[Jenno]

Wow it looks very different to mine. Very strange.

 

[Jenno]

Apparently if you do not have parking assist steering , then parking sensors are connected directly to the onboard supply control module (J519). That must explain it. I'd best find a local auto electrician to remove bumper and check wiring. Not pleasant driving a bus this big with no rear sensors. Thanks for all your replies on this.

 

[Stig414]

Irrespective of what module is fitted, the loom will have minimal differences. I still strongly suspect that the loom is broken just after it comes into the car. A continuity meter will help pinpoint the fault, but ideally, the bumper needs removing and the loom taking off it. It is a simple job but not a job for a wet windy weekend.

 

[Jenno]

Irrespective of what module is fitted, the loom will have minimal differences. I still strongly suspect that the loom is broken just after it comes into the car. A continuity meter will help pinpoint the fault, but ideally, the bumper needs removing and the loom taking off it. It is a simple job but not a job for a wet windy weekend.

Stig414 You were spot on with your theory. Took the car to a local guy who found a corroded wire in the loom where it comes into the car. Not sure how this can happen in a dry environment but its amazing to have them working again.

 

[Stig414]

Glad you got it sorted mate

 

[Brett1984]

Stig414 You were spot on with your theory. Took the car to a local guy who found a corroded wire in the loom where it comes into the car. Not sure how this can happen in a dry environment but its amazing to have them working again.

Hi Jenno,

I have exactly the same issue right now same year motor as you, had all the back trim out no module there after all that, managed to find this thread now hoping with that when I take the rear bumper off its the wiring loom fault that my brother can repair. fingers crossed