Question for the MOT examiners.

[Laird Scooby]

Originally Posted by Ian21401

Dave,
Not sure whether he was measuring the control voltage. He did have his meter probes in the connections to the car’s harness and the connections into the module. I may have a look with my meter. I’ve found a CANbus tutorial on YouTube which seems to explain things and I will be revisiting it.
The ‘van has electric hookup so there has not been any battery issues as it charges when on EHU and the battery spends winter in our garage connected to a CTEK mxs 5.0 smart charger. It’s just one of things that should work but doesn’t and it bugs me.

I take it the lack of on vehicle charging started happening after the last service Ian when it seems the tow socket electrics also packed up?

[S60D5-185]

Originally Posted by Ian21401

As of now, no contact from the main dealer.

Incredibly bad, verging on ignorant service

The upside of that is that we will then have an almost complete spare harness.

If you do need to purchase a full harness just to get a replacement module, can I suggest that you price up the genuine Volvo harness and module. John or Jack at Mill Volvo Sunderland parts dept always try to give a good discount if you mention the club and ask for discount.
It is plug and play and everything will work. Don't bother with the oft mentioned additional dealer download



I then removed the socket and wiring and booked an MOT with a local reputable tester. The car was duly tested today and now has a valid MOT cert. so, just for the hell of it, we may just go to the storage and try connecting up the ‘van. I don’t expect it to be working, but it’s worth the try.
Whilst we are fiddling with this, we may just find out why, when coupled up in the past and everything appeared to be working, including the ‘van fridge, the ‘van battery did not receive any charge.

Did the guy that checked things out for you not try a trailer board to see what was working ( or not )?

Good luck Ian, at least the car is back on the road now.👍😊

[37 RUBY]

Ian

Good to see the car is back on the road.

You could go second-hand https://www.ebay.co.uk/itm/Trailer-M...edirect=mobile
...but no guarantees.

However the attached document suggests extended periods of vehicle inactivity can cause communication errors and basically guides you to powering down the vehicle including removing fuses to dissipate residual voltage. Has that already been tried?

[S60D5-185]

Originally Posted by 37 RUBY

Ian

Good to see the car is back on the road.

You could go second-hand https://www.ebay.co.uk/itm/Trailer-M...edirect=mobile
...but no guarantees.

However the attached document suggests extended periods of vehicle inactivity can cause communication errors and basically guides you to powering down the vehicle including removing fuses to dissipate residual voltage. Has that already been tried?

Yes, I saw the used one on ebay but as you rightly say , no guarantee that it will be any better than the one already with the car.

The PDF that you provided is definitely worth following before doing anything else👍

[Ian21401]

Following the trailer wiring technician's visit and advice we took the car to the storage site and coupled up to the caravan. None of the road lights on the van worked but the "Fail Safe" brake lights did work, as they should. The permanent live 12 volt feed worked to operate the van interior lights. The "smart" relay is working as the fridge operated in 12 volt mode when the car's engine was running and stopped when the engine was switched off. I couldn't check the battery charge as the van battery is not in place and I had forgotten my multimeter.

SD60-185, The towing electrics are not Volvo. The harness is a dedicated for Volvo harness supplied from P F Jones. It is plugged into the two dedicated plugs of the car's harness with a 50 amp fuse, installed by the wiring installer, into fuseway 12 in the cargo area rear electrical centre. There is no fuse installed in the dedicated fuseway 4. The harness instructions advise that it is not necessary to update the car's software to "approve" the wiring.

Dave, The lack of battery charging from the car was not due to the service etc. as it has never worked since the trailer wiring was installed and because the van has only been used for short trips to an EHU site I have never got around to trying to sort it.

37 Ruby, Thanks for the CFC reset pdf. It is certainly an option but my daughter is loathe to use it lest putting the CANbus to sleep may create another problem. The technician did suggest powering down by disconnecting the car's battery, but we resisted that for the same reasons.

I have made enquiries with P F Jones, the supplier of the wiring harness, and forwared to them images of the trailer module. They have advised that they are able to supply a replacement updated version of the module to replace the one we have. It should simply plug in in place of the original. Cost £55.00 delivered. So I have ordered one. I'll update again once fitted.

[Ian21401]

Here goes,



















Seems to have worked.
Edit: the title should read Images.

[Laird Scooby]

Originally Posted by Ian21401

Seems to have worked.

Excellent news Ian!

I wonder why they felt the need to update the module though - perhaps they're aware of a software glitch on the Volvo that Volvo won't admit to?

[andy_d]

Originally Posted by Laird Scooby

Excellent news Ian!

I wonder why they felt the need to update the module though - perhaps they're aware of a software glitch on the Volvo that Volvo won't admit to?

could be
could well be
"improved it cos they could"
"changed it as they found cheaper components that work as well"
"cost saving something else powered by accountants"


being me id plump for the "some accountant worked out how to save 3p per module"

[Laird Scooby]

Originally Posted by andy_d

could be
could well be
"improved it cos they could"
"changed it as they found cheaper components that work as well"
"cost saving something else powered by accountants"


being me id plump for the "some accountant worked out how to save 3p per module"

Normally i'd agree with any/all of your suggestions as to be honest, the most likely probability.

However, given Ians experience of the original type modeul no longer working and the new one working immediately, it suggests they change was necessary.

There was also a thread some time back (about a year?) where the OP had a new XC and a new caravan (think they were bought in 2018) and the LED lights wouldn't work properly on the van. Given he'd paid a lot of money for both new (car and van) he was understandably upset when told he had to change the trailer towing module for the lights to work correctly. Whether he did splash out on a new module and if that sorted it i can't remember but i think Volvo should be explaining a few things.

[DaveNP]

Originally Posted by Laird Scooby

... but i think Volvo should be explaining a few things.

It's not just a Volvo thing. Slightly different department but our trucks at work, all relatively new, often don't play nicely with some of the trailers, often the newer trailers; it's almost routine to get a dashboard warning for failed lights but on checking visually there's no problem, the only solution is to get the tech in who then has to reset or install programming/firmware to the truck/trailer. It would seem that there are a number of manufacturers and systems and none of them are prepared to tell the others what they are doing, presumably on the basis of 'commercial advantage', and the consumer has to deal with the fallout, way back when ABS was first coming in it was a similar situation but the safety angle seemed to get them all to cooperate in the end.