V50 Trailer Control Module
 

Hi all, tried asking this in the V50 section but no luck. Anyone know?

I've just fitted to my 2009 V50 a second hand towbar which came with a used volvo trailer module. This is currently plugged in and powered up but not doing anything as the car presumably isn't talking to it. Does anyone know for definite if this module can be reprogrammed and used? Local dealer wasn't sure but thought if it hadn't been de-registered from its original car, they wouldn't be able to code it to a new one. Does that sound right? If so would seem to make all the second hand units for sale on the internet worthless! I'm guessing its the CEM that actually gets reprogrammed, to look for the trailer module with the correct serial number?
Towbar came from a scrap yard so doubt the original car still exists!

I am sure you are right. The basic function ie lights should work straight away and you only get the full functionality when you have had the software downloaded at a dealer.

There was a thread on here a while back that said that you had to deregister the module from the donor before you could use it on another vehicle.

You have made a good saving on the towbar so bite the bullet and buy a genuine Volvo module to get the full functionality.

I've got no functionality at all atm, let alone the extra software stuff.
I can see the TRM in vida fine, but as its not in the car's configuration table nothing doing.
Maybe if a car is already configured with a tow module, which subsequently goes faulty, then a second hand spare might work I don't know. Even then don't know how you get around the serial number being different.
Was hoping not to have to stump up for a new module plus software and dealer time as the cars now quite old and only worth about £500! Looking more like a cheap bypass relay, which is a shame.

The trailer modules are not coded to the car but do need a software update to recognise them - until the software is loaded, nothing usually works. This means you have to go to a dealer or a good indie will licenses VIDA. Whilst VIDA might see the TRM as it's on the canbus, the CEM needs software to talk to it.

You can buy generic trailer modules that don't need programming or software but they won't have all of the functions such as bulb failure warning, parking sensor defeat or fog light control. Most towbar outlets will sell them. Or you could just buy a relay and splice into the wires - will work just as well....

https://www.pfjones.co.uk/volvo-v50-...9260500pf.html