Hi all,

 

My parents have a 55-plate Octavia Elegance, on which the parking sensors have stopped working - apparently they were working on Wednesday morning, but not in the evening.

 

When they put the car into reverse, instead of there being a short "beep" and an image of the vehicle appearing on the radio, there's a long "beep" (denoting a fault), and the radio stays blank.  I've plugged a hand-held VAG fault scanner into it, and it hasn't revealed any fault codes that are obviously related to the parking sensors being logged (the only one that might be is a Data Bus Comfort working in Single-Wire Mode [marked as sporadic, suggested possible open circuit]).

 

So, before it's sent off to the garage, does anyone have any ideas what the cause may be?  A Google search suggested maybe water ingress (and it's not like it hasn't rained recently! ) or the sensor becoming unplugged..?

 

Thanks for any suggestions

You should be able to tell which sensor is faulty by cupping your ear over each sensor when the car is in reverse ( the engine doesn't need to be on for this ) they emit a clicking sound if working correctly. There will be a fault stored if the car emits the long beep, but will need VAS or VCDS to read it.

You should be able to tell which sensor is faulty by cupping your ear over each sensor when the car is in reverse ( the engine doesn't need to be on for this ) they emit a clicking sound if working correctly.

Cheers - will try this.

 

There will be a fault stored if the car emits the long beep, but will need VAS or VCDS to read it.

Ah, I guess my hand-held fault scanner (Gendan's "VAG Pro" one - I believe it's a rebadged Autel MaxiScan) - isn't able to read that system then ..? :(  I know what VCDS is, but what's VAS?

VAS is the dealer diagnostic tool, there are some that crop on ebay.

Your handheld scanner usually only reads the engine ECU and none of the other systems.

VAS is the dealer diagnostic tool, there are some that crop on ebay.

Ah, cheers

 

Your handheld scanner usually only reads the engine ECU and none of the other systems.

The one I got was supposed to do the electrical systems as well (e.g. air conditioning, radio, steering wheel, instruments, central locking, central convenience), too - I guess it doesn't extend to the parking sensors. :(

Does your reverse lights work? As if not then the reverse light switch wire may have snapped as the switch also triggers the sensors

Could be water behind the sensor. As above find the duff one and they're pretty easy to fix.

If you can't hear them click, they're dud.

They're sealed units so I don't believe the water ingress theory but many do.

Best price I found on eBay was £12 each with free postage for brand new UK sourced items when I replaced 2 last year.

I'd been having issues with my front nearside sensor for about 6 months. It was working in the dry but as soon as it rained I just got the long beep. Then, about Xmas time it stopped working completely, I assumed it was a faulty sensor but when I swapped it out it still didn't work.I took the bumper off and discovered that the cable had been rubbing on one of the brackets and had completely severed! Its worth swapping sensors around just to confirm its the sensor before buying a replacement.

Thanks for the help guys - it is appreciated! (and has been mentally filed away for future reference)   

 

Annoyingly, they started working on Friday afternoon (and have been working without interruption since), so it looks like it might have been the case that some water/damp had got in there, and the recent sunny weather had heated the panel up and dried it out (well, that's what I'm hoping!).  I will take into account what Mr G 76 said, and check the cables for signs of deterioration when we get a semi-warm weekend, though!

I also need a couple of sensors, but don't actually know which ones. can someone paste an ebay link to the right ones here please. I have an estate so don't know if they are different but thanks to anyone who does!

For my 2006 hatch the part number is 7H0 919 275 C . Put that part number into eBay and you should get plenty of choice.

For my 2006 hatch the part number is 7H0 919 275 C . Put that part number into eBay and you should get plenty of choice.

 

Same as in my Audi A8, just bought one of these genuine sensors due to my nearside front playing up when its wet.

http://www.ebay.co.uk/itm/321047752249?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

They come unpainted, so you'll need to factor in painting.

Hi all,

 

Sorry for the late bump.  The parking sensors have been working intermittently since I said they were working (worked for about a week and then went intermittent) - I've had a look and the spare wheel well had a bit of water in it.  It would appear that one of the sensors isn't fully sealed against the bumper, leading to water getting in, and travelling along the cloth lining of the cable, which was rather damp.  Have dried it out with a hair dryer, and it's been working since (but obviously need to do something to improve the sealing).

 

Don't know if this is of help to anyone.