Parking Sensors

[stuffedpike20]

...on my friend's Fabia are playing up.

Sometimes it is OK, but sometimes he gets a continuous tone upon selecting reverse, and the graphic shows the car is too close to something when it is close to nothing.
A google search says it is almost certainly a faulty sensor. Youtube shows people 'curing' the problem by squirting the sensors with WD 40. He has tried this, but the problem still exists intermittently.

The rear bumper has to come off to get at the sensors, which is a pain in the proverbials. He is not sure how to tell which sensor might be faulty.

Any ideas?

Thanks,
John

[oliver90owner]

Sensors may well need to be correctly orientated to operate correctly?

[rocco]

When I had this problem on my old Galaxy, it was the wire that was the problem, not the sensors. Visual inspection once bumper is removed and then a simple continuity test to confirm. Saves spending money on sensors if not needed although checking the pins for corrosion is also worth doing.

[stuffedpike20]

Thanks folks.

We were hoping to not have to remove the rear bumper.

I think if it starts to fail every time; we will have to remove the bumper.

[Guildbass]

Some VW group sensors were dealer fitted and these are often black rather than colour coded to the car's plastics. On those, the control box is behind the trim in the rear on the nearside. I think you can identify the dodgy sensor by pulling wires.
It is often one of the two on the outside and those can be got at without the bumper coming off.
Most fault finding I have watched involves substitution with a working sensor as unless the sensor has been pushed in and is working but simply 'seeing' the inside of the bumper, they seem to default to 'tone' when they fail.
Not easy to filter find without taking the bumper off and having a new sensor to swap with the originals

[Sleeper]

The sensors are a little fiddley but easily accessible...

rev.jpg (907.48 KiB) Viewed 3759 times

P.S. I don't know why it's upside down..... Admin ?



John ;-)

[alanworland]

They work on ultrasonics and can be heard (up close) clicking or even felt to identify which isn't working.

Alan

[Mercmancdi]

Is it possible to reach over the rear of car from the side with a strip of light wood etc and test each sensor.
The last ones I fixed needed blew out with air then from behind a light heat from a heat gun with patience to remove damp. This did cure it and I then was able to reach in and with a screw driver put black mastic around the connection, it cured that one. Damp can be a common problem. I have had 3-4 that were changed but were fine after sitting in garage for few weeks in the dry.

[stuffedpike20]

I just left mine, and at the moment in the present hot weather they are working fine.