S Type Sensors not working

[John D9395]

Since polishing the car, the rear sensors haven't worked all the time. Sometimes, when you select reverse you get a long beep (different pitch to normal), then it goes off. If this happens the sensors fail to detect / warn.

I am asuming it was caused by the polish. Have tried cleaning with washing up liquid, bug remover.

Has anyone else had this problem. Is it the polish, or another fault / coincidence.

Any help appreciated

[Nefarious]

See my other post on parking sensors - find the offending sensor (and confirm that its not the control unit). Pop it out and give it a good clean, and use some contact cleaner on the plug. Failing that, it's probably just a coincidence that it failed after a wash.

[John D9395]

Nefarious

Thanks for your reply.

Done the test which I found from your earlier post. Got my 8 year old to sit with his foot on the brake whilst I stood behind. 3 of the 4 sensors generate like a crackling sound, whilst the 4th is silent.

Might be a dumb question. The sensors are 'colour keyed'. Is this a cover, ie the sensor is behind, or is the grey bit (in my case) the sensor.

As earlier post, I had just polished the car, and I seemed to remember reading that certain polish can effect sensors.

What do you think, too much polish, or new sensor required.

Are they easy to fit, or do you need it to be programed to the car in anyway, ie DIY or main dealer.

Thanks

John

[Nefarious]

Not quite sure what you mean by colour keyed.

The sensor itself is a cylinder shape, and as you look at it endways on, it's a circle with either a smaller circle, or a lozange shape inside. It's held on with two little plastic clips on the inside of the bumper.

Pop your head up behind the bumper, undo the little plug and prise the two plastic lugs apart, then push the sensor inwards to remove it.

The first thing I'd do is swap two sensors around to rule out a wiring problem.

Assuming it is a sensor at fault, then give it a good clean (use a strong fairy liquid solution if you're really worried that polish could have affected it), and clean up the contacts on both the plug and the contacts on the sensor with contact cleaner (or white spirit).

If all that fails, then yes, you're into a new sensor.

[John D9395]

Thanks.

By 'colour keyed', I mean the bit you can see is the same colour as the car, not a black sensor on a red bumper etc.

I am sure this will all become clear to me when I get under the car.

Thanks again