Hello,

 

I have a 2006 Petrol VRs Wagon, which I've owned for about 4 months. At the weekend the parking sensors started playing up. I'm assuming they are factory fit, rear only, and I usually get both the audible warning and the visual proximity bars on the standard radio display.

 

When I put the car in reverse, I get the short high pitched tone, and then a continuous tone, indicating that I'm reversed hard up against something, when in fact there's nothing but fresh air behind. The visual proximity display also indicates an obstacle right behind, although the level of proximity on the display can be variable, even though I'm not moving! The fault is a little intermittent but is much more often present than not.

 

Over the weekend I transported a couple of 25litre containers of aquarium water, which weren't restrained as well as they should have been. My suspicion is that they may have thumped the parking sensor controller or loom, and dislodged something. Plan of attack is as follows:

 

1. Scan the car with VCDS to see if there are any faults. Did this yesterday, nothing flagged:

 

Address 76: Park Assist        Labels: 1Z0-919-283.lbl
   Part No SW: 1Z0 919 283 B    HW: 1Z0 919 283 B
   Component: Parkhilfe 4-Kan H04 0020 
   Coding: 0000001
   Shop #: WSC 73430 790 00000
   VCID: 3D7A27126462C0F6B0B-8068

No fault code found.

 

Q1. Might this change if I put the car in reverse and then re-scanned?

 

2. Do the click test to ensure all the sensors are working (haven't done this yet, will do tonight)

 

3. Try and get at the controller and unplug it and plug it in again and ensure the connections are good

 

Q2. I understand that the controller is on the rear of the wheel arch on the passenger side. Can anyone give me some detailed guidance on how to get the carpet panel off? It doesn't look obvious. I also have the multidisc CD changer in the way on that side.

 

4. Have a scout around the bumper and see if I can see any damage to wires where they go through the bodywork (haven't done this yet)

 

5. Give up and get the dealer to sort it (would rather not spend the money)

 

My wife and I share the car - I need the parking sensors to protect the paintwork. If I don't spend the money on the sensors, I'll only end up spending it on paint!!!

 

Any help most appreciated.

Thanks

 

 

 

Unlikely that the containers will have damaged the loom or controller as they are well hidden behind (mostly) plastic fittings.

 

Do the 'listening for clicks' test and also clean the sensors as it is not uncommon for them to be covered in a thin layer of dirt (even water) that can upset the system.

 

When you say you get the visual display - is this showing all sensors are in close proximity to something or only specific sensors? This may give a clue as to what is happening.

 

Q1. unlikley. Fault codes get stored.

2. Do this as soon as you can.

3. Doubt that it will make any difference as the plugs are very secure normally.

Q2. I can, but it will take time to type up and I no longer have an Octavia to be able to take pictures of. Search on here and you should find quite a lot of the information already there. It is not too difficult, but is time consuming and a little scary the fist time you do it.

4. It enters the interior in the centre of the vehicle into the boot. It passes through stiff rubber grommet so I doubt that there is damaged at point of entry. Most likely any damage will be behind the bumper. However, if you had a damaged wire, you would get just a continuos beep and no display as the whole system has to be operational or nothing works at all.

5. That sounds expensive...

 

My hunch is that the sensors are dirty, wet, covered in wax, etc.

 

HTH

Edited 27 January, 201511 yr by KBPhoto

Thanks for the advice.

 

I did clean the sensors last night as the bumper was very dirty. But it didn't make any difference. I may try blowing them with an airline....

 

My display doesn't show the individual sensors. Just an icon of the car and two sets of bars against the rear left and rear right (although there are 4 sensors on the rear bumper). I think I have the 'Stream' stereo. It has a single CD slot and the changer in the back. It is showing full proximity (i.e. very close to something) on both sides, but the right hand side was fluctuating between full proximity and about half.

 

On one occasion last night I engaged reverse and the system worked. But when I tried again, it went back into failure.

 

I'll spend a bit more time tonight on searching for the quarter panel removal instructions. I'm not particularly familiar with searching in forums (fora?)

 

Re the click test - do you just hear one click when you get within a particular distance of the sensor, or are they continuously clicking and get faster as you get closer? Just so I know what to listen for!

 

Thanks again

Trevor

You may have a loose connection to the reverse switch. I did and had the exact same behaviour as you describe. Easy way to check - if the behaviour happens again, check if yr reverse lights are on. If not, the wires to the reverse switch are under the air box in the engine and a known weak spot.

If you do still want to get at the controller, I wrote it up as part of a bigger project here: http://www.briskoda.net/forums/topic/261422-pdc-ops-advice/page-4

Adam

Edited 27 January, 201511 yr by adamal

Thanks guys. I just did the 'click' test and all four sensors are clicking away merrily, so I guess no problems with them then? Correct me if I could  be wrong.

Whilst doing the check, I noted that the reversing lights always come straight on and are steady - so probably not the reverse switch.

 

Bizarrely, whilst I was doing the click test, the continuous buzzing stopped and things started working normally again. Being the pessimistic animal that I am, I took it out of reverse and put it back in, and was back to where I started. interestingly the proximity bars on the display seem to wave about independently. As if something was moving around at the back of the car (nothing is).

 

So, i'm back to having a go at the controller, or possibly the earths, i'll study the post that you linked to in more detail later. I'm half expecting that if I get in there, disconnect the controller, reconnect it and turn the ignition on, all will be well again. If not, and the earths OK, then something is definitely kaput and it's time to get my wallet out. Kinda surprising that the VCDS check didn't flag any faults though. 

 

Any further suggestions appreciated.

I would say that if the wiring or module is at fault a vcds fault should be showing.

I agree with Adam. Any wiring or controller fault will almost certainly show up on VCDS.

 

The sensors themselves and most switches are not covered by the scans.

I would have thought so too. But I'm out of ideas otherwise. I cleaned the sensors with kitchen cleaner last night, which goes with Addicts suggestion above,  but no joy.

When I did the scan yesterday I did the 'reset all controllers' bit, but there were no errors before hand ( I saved the scan log). I will have a look at the reverse switch at the weekend though. 

So the reverse switch may well be the most probable, if the clicking sensors means that they are all AOK.

Is the reverse switch easy to get at under the airbox - sorry very lazy to just ask these questions without having a look, but I've only got Saturday morning to do it. Then I'm off snowboarding for a week, leaving my wife to reverse into whatever she wants to, at will 

I would say most likely but did you not say the lights were OK when the continuous beep was in play? The other thing could be a dodgy speaker (in passenger b pillar). When they fail I believe there is a continuous tone too.

Thanks 

The reversing lights are fine all the time, whether there is continuous beeping or not. 

The speaker is an interesting extra point.

Is the reverse switch easy to get at under the airbox - sorry very lazy to just ask these questions without having a look, but I've only got Saturday morning to do it. Then I'm off snowboarding for a week, leaving my wife to reverse into whatever she wants to, at will

Yes pretty easy. Remove the MAF sensor plug, undo the big pipe clip and also the airflow entry pipe (which clips out) and its a couple of screws as I recall.

Adam

Thanks

The reversing lights are fine all the time, whether there is continuous beeping or not.

The speaker is an interesting extra point.

They can be had cheaply enough from www.carsystems.pl to buy one to test it, but might not get sorted before you go...

The sensors are monitored by VCDS.  At least they were on my Bora and it even told me which one had gone.  Although the click test works just as well once you know what you are looking/feeling/listening for.

 

On my Octavia it very occasionally (I am talking only around 4 times in nearly 5 years) it thought there was something right against one of the sensors.  Nothing in VCDS so just assumed it was damp or dirt affecting the sensors..

 

May be worth removing them, cleaning them and spraying with contact cleaner?

Any luck in finding the fault? I've got the same problem, after changing a couple of faulty sensors it's still not working. All work with the click test, no beep or display just the little symbol flashing orange under the climate control. Any ideas?

I think the flashing light indicates an issue in the reverse circuit. Are the reverse lights working?

The reversing lights are on and all sensors front and rear are clicking. I thought it was a bit weird that the 2 front centre sensors and the same on the rear had gone down at the same time.

It could be a module fault then, and is probably a circuit fault if front and rear went down. Does yr rear washer work? The pipe can pop off by the module and the liquid gathers there potentially damaging it.

To be honest I don't think the rear washer does work. Do you know how to access the control module in the boot area? Is it more likely to be the control module rather than the buzzer?

It might be the buzzer but if so some sensors would not have worked which I think you are implying?

The module is above the passenger side rear wheel arch. Pain to strip the trim but taken from another post:

I started by taking the centre trim of the rear sill away (three plastic nuts by spare), then the lower d pillar trim (screws and clips), then the c pillar upper trim, and then the luggage cover support. You need to remove caps from the hooks to access the screws and also there is a screw behind the big hook. Then I pulled the rear seat bolster off at the top (just a good tug), and unscrewed the side trim. The rivet things by the cd changer (if you have one) pull out easily with a long nose pliers applied on the centre pin. This is for an estate, a hatch will be slightly different I imagine.

The last time the car got scanned by a dealer for a gearbox fault, the report said the 2 front centre sensors were bust and the 2 rear centre sensors. I will have a go at removing all the trim, from what you've posted about getting at the module it's a case of removing all the interior around the rear passenger wheel arch to get to it. Do you know if any module off a 2005 mk2 will work or does it have to be a specific model number?

If it is wet, you will want one specific to the pre FL for front and rear, but a scan will confirm that hopefully and I advise that first.

The part number was 1Z0 919 283 C on my car before I upgraded the controller to display on the Columbus. But you specifically need the front and rear variety which has the C suffix (or it has 8k rather than 4k in the description k being kan which is German or Czech I imagine).

Try ebay for the controller (sold mine for 30 quid on there sometime ago) or otherwise it might be the dealer. You can get the newer FL ones from www.carsystems.pl for less than 50quid I believe. The part number ends in 475 and still show on the Stream (I tested it) but they may need some rewiring. See http://www.briskoda.net/forums/topic/261422-pdc-ops-advice/.

Nice one thanks for that, hopefully find one on ebay for a few quid.

Yep good luck.