Tow bar error messages V90

[GaryB1969]

This car seems to be wanting to self-destruct at the minute..... Latest error messages:

It's a 2022 B4 with a Volvo tow bar, today (not towing, tow bar not folded out) I keep getting error messages saying the trailer lights aren't working and the usual "rear park assist will not work as I have a trailer attached" message that I normally get when towing. But I'm not towing anything!

It's as if the car THINKS I have a trailer plugged in, it thinks this hence I get the usual message about rear park assist disabled, BUT as it cannot detect any trailer lights (because there isn't any plugged in!) it keeps telling me they aren't working.

Anyone heard of this before? I have plugged the caravan in and the lights on that work properly with the car with no error messages.

It's booked in with the dealer for the previously mentioned parking sensor/rear auto brake problem but the dealer cannot look at it until April.

[GaryB1969]

OK just to add to this, the tailgate has now started closing on it's own. Twice this afternoon when in the open position it has just decided to close itself without being activated. There's obviously something amiss electrically.

All of the recent gremlins started AFTER it was jet-washed following it's main dealer service a few weeks back so it could well be water has got into somewhere that it shouldn't.

[Kugaman1]

As per another thread on here today, Id be doing the sunroof test I recommended to check for a drain blockage.

[vonRypp]

Originally Posted by GaryB1969

This car seems to be wanting to self-destruct at the minute..... Latest error messages:

It's a 2022 B4 with a Volvo tow bar, today (not towing, tow bar not folded out) I keep getting error messages saying the trailer lights aren't working and the usual "rear park assist will not work as I have a trailer attached" message that I normally get when towing. But I'm not towing anything!

It's as if the car THINKS I have a trailer plugged in, it thinks this hence I get the usual message about rear park assist disabled, BUT as it cannot detect any trailer lights (because there isn't any plugged in!) it keeps telling me they aren't working.

Anyone heard of this before? I have plugged the caravan in and the lights on that work properly with the car with no error messages.

It's booked in with the dealer for the previously mentioned parking sensor/rear auto brake problem but the dealer cannot look at it until April.

Some dirt might got into either the trailer plug connector under the plastic cap or other areas around the tow bar which might cause short-circuit. I would start cleaning that area.

[wynnj]

Originally Posted by GaryB1969

OK just to add to this, the tailgate has now started closing on it's own. Twice this afternoon when in the open position it has just decided to close itself without being activated. There's obviously something amiss electrically.

All of the recent gremlins started AFTER it was jet-washed following it's main dealer service a few weeks back so it could well be water has got into somewhere that it shouldn't.

Who jet washed it? If it was the dealer then it's 100% down to them to sort the problems and I would be pushing very hard for a priority appointment and/or a replacement car.

[nu11eaf]

Try cleaning the tow bar electric socket pins with WD40, did you inadvertently put your foot or something under the tailgate foot operation sensor resulting in the tailgate closing.

[Philip Fisher]

I would be hunting all round the boot well for water. The tow bar electrics plug in there and there is a module to run it in that location too.

[cassell]

I had very similar issues with my V90 with the genuine Volvo electric towbar whereby when not towing anything I regularly got the "trailer indicator light not working" also "trailer brake lights not working" messages. Like you, I plugged in my caravan and trailer and all lights worked perfectly.

It turned out to be a very slight water leak from the rear panoramic sunroof drain causing dampness on the trailer module under the offside boot floor. This was during covid when semiconductor shortages were causing parts supply problems so my Volvo dealer simply cleaned up the loom contacts on the module, rectified the leak area and the issue has never returned.

Hope this helps.

[GaryB1969]

Thanks folks. I located the trailer module in the O/S rear corner, unplugged everything and plugged it back in. Nothing was wet but trailer indicators still not working. It WAS the dealer that washed it but they’ve been awful regarding customer service. Fortunately I have found another dealer (Derby) who have availability on Monday afternoon so I’ll see what they can find. I’m convinced water has got somewhere. This is my second V90 and as much as I love them the experience with a certain dealer has tarnished it a bit.

[GaryB1969]

Originally Posted by cassell

It turned out to be a very slight water leak from the rear panoramic sunroof drain causing dampness on the trailer module under the offside boot floor. This was during covid when semiconductor shortages were causing parts supply problems so my Volvo dealer simply cleaned up the loom contacts on the module, rectified the leak area and the issue has never returned.

Hope this helps.

Thanks, mine hasn’t got a sunroof but it really does sound like a water ingress problem somewhere. Tomorrow I’ll try warming the trailer module with a hairdryer “just in case”.