Parking sensor dosn't work

[gustav]

Really - Aggressive

I can't see anything aggressive in my post to be honest, maybe you are being over-sensitive.

I had the same vehicle, a little earlier with front and rear assistance, so know that the test works on my vehicle - although if your car has gone into economy mode, it may not work of course.

As far as water can affect the sensors - yes, I speak from extensive experience on all 3 MK I, MK II and MK III C5s I have owned. Water can get up behind the bumper and if the wiring has become unsecured or is hanging in a certain way, any water can run back down the wire and into the sensor module itself causing the intermittent issues.

With this system, it is all or nothing - if any one sensor goes then the system does not work for safety reasons.

The other possible issue apart from a faulty sensor is that the ECU itself has been knocked, or has a bad connection in the wiring plug, or has had some liquid spilled onto the module that is causing problems, for which this also had that happened to me too after 5 litres of screen wash leaked into the boot floor and got into the ECU. It took several weeks to clean and dry it out.

These are just possible answers - but of course the best thing is to have it diagnosed properly with an appropriate diagnostic tool like Diagbox that will provide a fault code(s) and will help determine the cause.

Hello
I have the same symptoms as above so I am reviving the tread again. The error message is parking assistance system failure. The rear screen wash also stopped working a few weeks before the parking assisten gave up. Could this be related? Screen wash on the ECU in the boot?

[GiveMeABreak]

Not really - the parking assistance is completely separate ECU and uses a different wiring harness to the rear wash wipe.

Does the rear wiper motor work, but it's just the screen wash that doesn't? If so it may be the washer pump.
As for the Parking ECU if one or more of the parking sensors is malfunctioning, then the whole system packs in. If you have Diagbox, run a diagnostic and it should tell you which sensor is faulty if this is the case.

[gustav]

No diagbox unfortunately, just an ELM327 obd2 with Carscanner on my android phone. Not sure what Im able to see....
Rear wiper is working fine so probably the rear washer pump.
A thought: if the pump is working and the culprite is a broken hose. Is it in that case possible that screen wash can find its way to the parking assistent ECU?

[C5-NON]

A quick look to see if your boot floor is full of screen wash might answer that. My hose split were it comes out the top of the back of the car when you open the boot (on the tourer). I fixed it with a length of pipe and a couple of hose clamps.

[jml]

To tapkaJohnD, re your post on 13/2/21.

I have never seen Marc to be agressive and I certainly didn't see any aggressiveness in his helpful response to you - unless you took his description of your mechanic's diagnosis as 'baloney', which it most definitely was.

You couldn't find anybody more tirelessly helpful than Marc.

[gustav]

Not really - the parking assistance is completely separate ECU and uses a different wiring harness to the rear wash wipe.

Does the rear wiper motor work, but it's just the screen wash that doesn't? If so it may be the washer pump.
As for the Parking ECU if one or more of the parking sensors is malfunctioning, then the whole system packs in. If you have Diagbox, run a diagnostic and it should tell you which sensor is faulty if this is the case.

Hi again!
Im thinking of buying a diagbox. Any specific one U recommend?

[GiveMeABreak]

Many here buy theirs from Easydiagnostics. Great backup support and there is a discount for members:

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