Reversing sensors / Towbar

[iscacamper]

Hi,

I'm sure this kind of thing has been discussed before, but I am hoping someone has some advice on my specific problem.

I have recently bought an '07 Octavia Estate which has a flange towbar fitted. There is an intermittent problem with the reversing sensors, whereby they will sometimes register a 'phantom' object when there is nothing there. This usually happens for brief periods, comes and goes, and sometimes doesn't happen at all.

My suspicion is that the towball is causing the problem. However, since the towbar was already fitted to the car I'm a bit surprised the previous owner didn't have a problem with it.

I have previously driven an Octy Estate with a swan neck towbar which had no such problems.

I have checked that the sensors are working by listening to them, and they are all clicking away nicely and responding when I put my hand in front. The dashboard display and audible alert seem to be working correctly.

So I was wondering - is the towbar the likely culprit, or is there a possibility of some other fault?

(Before anyone suggests removing the towbar, I need it!)

Thanks!

Edited 3 January, 2013 by iscacamper

[silver1011]

It sounds like the towar to me.

Can you not do without it for a few days, remove just the ball / hitch and see if the problem goes away, it only takes a few seconds to remove it and reattach it.

You'll probably find the previous owner just accepted the issue and put up with it, I'm not really suprised he didn't volunteer the information when he sold it to you

[iscacamper]

It sounds like the towar to me.

Can you not do without it for a few days, remove just the ball / hitch and see if the problem goes away, it only takes a few seconds to remove it and reattach it.

You'll probably find the previous owner just accepted the issue and put up with it, I'm not really suprised he didn't volunteer the information when he sold it to you

The car came from a dealer, so I doubt they would have even noticed.

Yes, I could try removing the towball and see if it solves the problem. If it does, I guess I'll have to either live with it or change to a swan neck towbar.

Cheers,

[mattytemp]

Try looking for water in or around the sensor. I had same problem got a dry spondge on them and it cured the problem. Could be your problem specialy with all the rain weve had.

[iscacamper]

Try looking for water in or around the sensor. I had same problem got a dry spondge on them and it cured the problem. Could be your problem specialy with all the rain weve had.

OK, thanks, I'll try that. I've just taken the cover off the towball and that seems to have improved matters, but it's too early to say if it's cured it. It didn't have a cover on when I got the car (I added it afterwards) so maybe it adds just enough extra bulk to trigger the sensors.

[Duncan Grier]

is it oem wiring / kit or a relay type setup

I went for the oem setup which via recode will disable reverse sensors when you are towing along with TSP, alarm for trailer etc etc

DG

[iscacamper]

is it oem wiring / kit or a relay type setup

I went for the oem setup which via recode will disable reverse sensors when you are towing along with TSP, alarm for trailer etc etc

DG

It's a relay setup. I'm not bothered about the sensors triggering whilst towing (they would only trigger when reversing, and I avoid reversing a trailer as much as possible ). It's when there's no trailer attached that it's a problem.

[M12MKD]

My removable tow bar does not cause this issue. Im guess yours is not a removable one so maybe thats the problem.

Though I get ghost reading on the front sensors sometimes, usually its caused my water in the sensor.

Get a tissue and pat dry, cup hands over sensor and huff on it a few times then hold the tissue over it again. This always solves the issue!

[ianbenny]

Have you got a bumber baffle plate behind the hitch. This caused a false reading on my Mondeo. I have a swan neck (fixed) Witter bar fitted without any problems with the sensors

[kevberlin]

Took my Octy for service today and told them the front offside sensor was continually picking up non existent walls/obstructions.

Result. Skoda dealer ran a test on each sensor ( saw the diagnosis report ) and identified a failed sensor. New one on order under warranty.

I had wrongly assumed there may have been water in it and that the problem would go away in due course.

[iscacamper]

Hmm, looks like the problem is still there even with the towball cover removed. It seems to come and go, and mainly happens in damp weather. The phantom obstructions appear randomly on either side (or both sides), so I doubt it's a dodgy sensor, otherwise I would expect it to always be the same side. So I guess the flange towball is the cause of the problem. I will remove the towball for a few days to confirm whether it fixes it (though I won't be able to remove the electric sockets without unwiring them - too much hassle!).

So either I learn to live with it or get a removable towball fitted.

[HUD Engineer]

Where did you get to on this?  I have a similar problem, but no towball to explain it.  All four sensors are clicking steadily, but phantom obstructions are being reported.  Sometimes they do work properly for a few seconds, and I suspect that only happens during sustained dry spells.  I keep the car clean, and don't jet wash the car, but when they are playing up, drying them with a tissue does not remedy them.  I've resorted to WD40, to see if it can chase any damp out, and I'm already thinking of giving each a gentle bake with a hair drier, to see if I can make them behave, but not feeling too hopeful.  Now that we don't have incautious children playing around our cars, the sense of need is reduced, so I may resort to disabling the system rather than living with the noise and mistrust that they are inducing.  I seem to recall someone suggested dampness on the back of the sensors, where the wires go in, but cannot refind that article, if it was on this forum, as I suspect it was.

 

Thanks,

 

Andy

[donmcknz]

I have the same problem with reversing sensors on my 2006 1.9 Elegance hatchback despite being assured by Witter before ordering it that the flange type towbar would not interfere. Removing the ball-cover helps minimise interference but does not eliminate it so to avoid random annoying false alarms I just unbolt the towball when not required - as Silver 1011 says it just takes a minute

DM

[silver1011]

This was the reason I went for a slim detachable.

 

No interference with the reversing sensors...

 

 

Edited 12 January, 2014 by silver1011

[mikey vrs]

The following might be worth a try,my dad bought a jag x type est with a towbar fitted & when i serviced it i noticed a ring a white insulation tape wraped round the tow ball cover so i removed it,soon as i engaged reverse i got the constant tone.....i re-fitted the tape & the fault had gone & has worked fine for the last year,maybe worth trying that on yours? 

[HUD Engineer]

OK, so in my case - phantom obstructions, and no towbar - One generous dose of WD40 sprayed onto each sensor and the excess swabbed off with kitchen towel seems to have restored them to normal operation. They have been back to normal for about two weeks so far. Reversing is no longer the audio annoyance that it was. Call me happy.

[HUD Engineer]

More than two years on, the WD-40 sprayed liberally into the parking sensors seems to have been very effective, and I've not applied any more so far as I can recall.

 

Andy