Reverse parking sensors

[PeteK]

Since I bought my 2004 Passat TDi about a month ago, the park assistance system has failed to work. When the vehicle is put in reverse the system emits one beep followed by a constant higher pitched beep which stays on for a couple of seconds.

However after a period of heavy rain last week, the system started working perfectly until the vehicle dried off. The same thing happened again yesterday; when the exterior of the car is thoroughly soaked it works perfectly, when dry it doesn't.

Any ideas as to what could be causing this?

Pete

[PeteK]

Any ideas at all guys?

The system is still only working very occasionally, i.e. only when all the sensors are soaking wet.

[hotrod09]

If it works when it is wet it would suggest that you have a wire that is either open or grounded when dry. Since the car should remain dry inside (yeah I know in theory) I would try to get under the car and have a look at the wiring coming forward from the bumber. Might just be some chaffing ...

[PeteK]

Thanks for the advice. Will check the wiring when I get a spare minute.

[PeteK]

I've just received my new VAG-COM lead through the post this morning and after clearing my airbag light (it's amazing what you can do with with this kit!) I did a check on the park assistance system and found the following:

VAG-COM Version: Release 409.1-US

Control Module Part Number: 3B0 919 283
Component and/or Version: Parkingsyst. PA RDW D01
Software Coding: 00104
Work Shop Code: WSC 00028
1 Fault Found:
01546 - Sensor for Parking Aid: Rear Mid-Left (G204)
37-00 - Faulty

I will carry out a check on the wiring to the sensor and maybe try swapping it with another sensor to see if the fault code changes. If there is an internal fault on the sensor, is it possible to by-pass the sensor so the system still works?

[Col]

Hello Peter,

Wonder if you can help me.

I've also got a 2004 Highline Passat which this evening I've fitted a fixed towbar to.

The problem is that the inner two sensors see the towbar and thus I'm getting a 'beeeeeeep'

At the moment I've disconnected the sensors to get rid of the 'beeeeeeeep'.

As this seems to be only only thread on here about B5.5 parking sensors I wonder if you know if there is a workround to this issue, i.e. recoding the unit to omit the inner two sensors.

Shame as the system was working perfectly !

[PeteK]

Unfortunately I don't think you can disable the sensors. I replaced the faulty one on my car at a cost of about £60 and then another 2 failed in the severe frost last year. I'm not willing to spend another £120 and just park the old fashioned way now using my eyes!

[davlin]

I have had my 2004 130 TDI for a few years now and I have noticed that as well. When it is wet it lets out a few more bleeps and then usally clears itself after a few seconds. I have also a tow bar fitted but I dont think this gives me any problems. I agree with Hotrod09 that the most obvious answer would be grounding but I recently got a replacement bumper after a knock and the garage fitted the old sensors back so you would asume that if they seen any bear wires they would have taped them up, but I still get those extra couple of bleeps when it rains and it happens also when I take the ignition key out and leave it sitting for a while and turn the engine on again, never when I have been driving, stopped and reversed?

Any ideas at all guys?

The system is still only working very occasionally, i.e. only when all the sensors are soaking wet.

[davlin]

Sorry I also meant to add the bleeps occur when I put the car in reverse and there is nothing behind me. (My driveway is on a hill and I have to reverse out onto the road).

Any ideas at all guys?

The system is still only working very occasionally, i.e. only when all the sensors are soaking wet.

[Charlie389]

I have a 2005 passat highline (with towbar) with reversing sensors that work fine in the rain, but for the last 2 summers when I'm reversing into bright sunlight or if the temperature is above about 18degrees all I get is a continuous beep. Late in the evening or early morning it's ok again. Anyone any ideas, apart from at least one (possibly 4) £60 sensor?