I bought my Octavia from a bloke who used it to tow his caravan. There are parking sensors fitted in the rear bumper but nothing is working. I would like to try and fix them but don't want it to turn into a major task. Are there any simple things I could check quickly, like fuses or reversing switch etc. Electrics are a bit of a mystery to me so I don't want to dig too deeply but it would be great if a simple fix was the solution. I think I read something in the manual about parking sensors being disabled when you tow a caravan.

 

Thanks in advance.

 

Normski

First thing to know to be able to give you advice is are the sensors factory fitted or an aftermarket kit?, because tools like VCDS will not be able to see or communicate with an aftermarket system. I would check your fuses first, then look in the boot for any fuses if the kit is aftermarket. Most factory fit modules for the sensors are behind the trim on the left rear boot trim inside the car.

 

Hope it helps

Hi Phil, thanks for getting back to me, sorry for the late reply. I will have a proper look this weekend now I have more time. I had a quick look the other day and found a 6 disc CD autochanger in the left hand recess. I didn't know that was there. I don't think it's plugged in though. Another electrical mystery. Normski

If the disc player isn't working and you have the oem head unit (people unplug the unit when fitting aftermarket unit) and it is still plugged in, then a common fault is for the rear washer pipe to dump it fluid all over the loom connector that runs in the n/s/r corner. This corrodes in time and causes issues like this, does you rear washer work ok?.

 

Oh and excuse my bad manners, welcome to Briskoda.

Edited 11 June, 20169 yr by kentphil1

Hi Phil, thanks for the info and the greetings. Now I know what to look for I've found it, it was actually staring me in the face all along as the unit is fixed to the near side wheel arch. It is a Skoda relay box of some sort so looks like they are OEM. The two plug in leads had been removed. I reconnected them but when I put the car in reverse the warning comes on straight away even when there isn't anything behind me. I think the sensors may be picking up the ball cover from the towbar. I can check this by removing the tow bracket as it is only a couple of bolts, get the ball out of the way and see if the sensors work OK. I don't need a towbar and would prefer to have the sensors working but I don't want to remove the towbar as it may suit a future buyer. If the sensors work I might remove the ball unit and tape up the electrics making reinstatement an easy option.

 

Re the disc player, the dashboard interface is a Kenwood model so I'm guessing this is not OEM, maybe it could not be connected to the multichanger. The rear wash wipe works OK.

 

I'll let you know how I get on.

 

Normski

If the parking sensor module is oem, you should be able to test the sensors with VCDS to see if you have a sensor messing about. You can also code the module to not work when you have a trailer on the hook.

 

As far as I am aware, the multichanger only works with the oem unit, and cannot be commanded by any aftermarket head unit as far as I know.

This is the instructions for a wiring dedicated kit for the octavia that you will see can be programmed for towbar and pdc, https://www.westfalia-automotive.com/fileadmin/pdf/e_anlagen/317/e317015391101-01.pdf it should detail the actual module and coding.  I think it is module 76, control code to 1, but don't quote me on that, it was nearly 4 years ago that I fitted mine

Hi Phil, thanks for all your help. The parking sensors are now working, sort of. They work OK but after it has rained I get a constant signal so I am guessing one or more of the sensors is faulty. Going to investigate the cost of a new set. Cheers, Normski

OEM kits come in reasonably expensive, I'll try to get a price and update, but you may only require 1 or 2 sensors, so the cost obviously reduces as you don't need the control unit.

 

Aftermarket kits come in about £15 - see here http://www.ebay.co.uk/itm/230405599727?ru=http%3A%2F%2Fwww.ebay.co.uk%3A80%2Fsch%2Fi.html%3F_from%3DR40%26_trksid%3Dm570.l2736%26_nkw%3D230405599727%26_fvi%3D1&_rdc=1 but you need to measure the diameter of the sensors you currently have to make sure the new ones don't flop around or worse still go straight through your bumper hole.

 

Do you know if your sensors are OEM or not yet?, if they are, you should have a VAG part number embossed on it's casing.

 

I get a constant signal for about 2 - 3 seconds after it has been raining, but as soon as the car moves enough to displace any water that may have bridged the sensor, (normally about a foot or so) they work fine for the rest of the day. Do you park nose down on a slope at all overnight?.

Edited 20 June, 20169 yr by kentphil1

Hi Phil, don't know if the sensors are aftermarket as I cant see, do you have to remove the bumper or do they pull out? They are colour coded to match the car and the control box is OEM so maybe they are genuine. Yes, I do park nose down on a sloping drive as it is not safe for me to reverse out if I park the other way.

To be fair, providing the sensors give you a varying beep as an object gets closer, then they are probably working correctly.

 

If someone stands behind the car when you have the car not running, but in reverse with the ignition lights on, do you get slow beeps at 1.5 metres, faster beeps at 1 metres very fast beeps at 3/4 metre and solid beeps at 1/2 metre?.

 

The rain thing is just something that seems to occur when parking on slopes, as I said, providing it clears quickly, there is not much wrong really.

 

If they are OEM, the unit will retain any fault codes and can be accessed via VCDS to ascertain the fault and code them to switch off when the tow socket is in operation.

 

In answer to your question about how they come out, it would be better if you have a picture of the bumper sensor on the back bumper to look at before I comment further.

Edited 21 June, 20169 yr by kentphil1