Re programming a car after fitting CAN bus tow bar electrics.

[Chris Bartram]

VCDS- see link above. You can buy it from the likes of Gendan. It's useful if you have multiple VAG cars like I do, and even more so if you do your own servicing.

[Andy Burns]

Well for an £1850 box they have to have and £250/year to keep it working, and a bloke's time, it's not so bad.

[Andy Burns]

But the car's eventual resale value will be lower

[Bill]

How on earth does it do that? I thought it would just turn them off.

My 2 likely trailers on the Range Rover are about 22' and 6' respectively.

How does it know (admittedly I haven't tried yet so maybe it brings up a question?)?

[Steve Walker]

What a rip-off. Cost me £20 for a lead to connect my laptop to my Vauxhall Zafira and came complete with a link to download software. Less than 10 minutes for me to enable and configure the trailer lights interface and enable cruise control (just had to plug in a different stalk and enable it in three locations).

SteveW

[Steve Walker]

If it is similar to the one for my Zafira, it will work when just plugged in, but it won't adjust the stability control for towing when a trailer is plugged in or check all the trailer lights every few seconds instead of just the indicators when used, without enabling those software options.

SteveW

[Steve Walker]

Ah, forgot. I think disabling rear parking sensors when a trailer is plugged in is also a selectable option.

SteveW

[Andy Burns]

Presumably when towing it turns them off, but when *not* towing it allows a few extra inches to stop you ramming stuff with the towball

[Andy Burns]

Well, that's why I started off suggesting finding someone who has a VCDS lead, I've done tweaks to my car with mine, and enabled extra functionality (such as dual SIM for phone/satnav) for a few locals, usually people pay "a drink or two" ...

[dennis]

It certainly checks the lights as it has informed me of a fault while driving.

I don't know about the stability program, the computer tells me a trailer has been connected.

[Chris Bartram]

Sorry, I was unclear.The extra length of the car with the towbar.

[Chris Bartram]

Yes, exactly that.

[bert]

I have a removable towball.

[Steve Walker]

I may have it the wrong way round on that and that function defaults to default to on, however with some trailers with LED lights it is necessary to disable that function to avoid all the lights flashing briefly every few seconds.

I forgot about disabling the rear fog light when a trailer is plugged in as well. Something you'd want to do with a caravan, but not with a narrow camping trailer without fog lights.

These things may happen anyway, but if you need to enable or disable a specific function you need a programming lead and software.

SteveW

[Harry Bloomfield]

Andy Burns wrote on 08/08/2017 :

Is the correct answer - mine is supposed to do the same. I guess if the proper towing relay is installed, that tells it to add the extra few inches of clearance to the reverse sensing system.

[Halmyre]

This is one of the things that slightly irritates me - manufacturers effect ively locking you out of certain functionality of your car. It's like ownin g a PC, and having to take it back to the shop for changes to the BIOS beca use I've added extra RAM or another hard disk.

Taking the PC analogy a step further, if manufacturers gave us free control over configuration changes, they'd still make money fixing all the problem s induced by blundering imbeciles.

[Chris Bartram]

I can't be certain, but I think there's a setting for that so it still turns off the sensors but /doesn't/ adjust the range.