New A4 Avant member with parking sensor problems!

[j_mcvic]

Hey All,

Ive just bought my first A4 Avant. Its a 2.0T with the auto box.

I'm having some bother with the rear parking sensors. When I engage reverse I get one long beep signifying there is a problem.

When I listened to the sensors there was only 1 clicking. I decided to move the one that was working from position 2 to position 1 where it stopped clicking. I moved the other sensor from position 1 to position 2 but there was no sound from that either.

From this I would assume that I have a wiring issue to position 1 (LHS). And sensor 1 is also faulty as it didn't work in position 2.I haven't managed to move the working sensor to position 3 or 4 to test them yet.

Is there any way to bench test the sensors to confirm if they are working or not before I replace them all and then try and trace the wiring back to see if thats faulty too? Can the control module be tested?

 

[AvantAlexB7]

Id start by to rotating the position of each sensor to eliminate a sensor fault before replacing. If it is a wiring fault checking the plug connectors for corrosion causing poor continuity would be an idea too as the plugs are exposed to the elements especially on the rear. Failing that maybe try diag software or vag com if possible. Hope this helps buddy!

 

[Beardymat]

Just try all sensors in position 2 since you know that works then move onto fault finding the wiring as Alex suggested.

 

[j_mcvic]

Just thought I would post an update in here for anyone in the future. Even though I had some strange results when swapping sensors around and also got some strange errors from VagCom i decided to order some new sensors. I just got some cheap ones from eBay for £10 each to rule them out.

So I fired them in this morning and the system is now working and its all good! Will see how long these cheap sensors work for and can look to change them for genuine ones in the future if needs be!

 

[MPP]

How hard are they to change? I've got a middle one playing up.

 

[Sp3no82]

I had to take the rear bumper off to fix one of my middle sensors on my avant. Took a good 1.5hrs just to remove it as you have to remove the rear seats, boot side panels, sub woofer jack the car up to get inside arch liners and all manner of stuff.

 

[j_mcvic]

How hard are they to change? I've got a middle one playing up.

I did them all without removing the rear bumper and with the tow bar still attached.

Each sensor has a plastic clip at each side which needs to be pushed outwards and the sensor pushed through from the front.

Then ones the sensor is loose from the bumper you can get into unclip the wiring. I had to use a flat head screwdriver to get the wiring clip to undo. Think it took me about 30-45 mins to change them all.

 

[Sp3no82]

Ahh the clips that held my sensor had come loose from the bumper so I had to remove mine to fix it. They are only attached to the bumper using double sided sticky tape!