I plugged my VCDS into an 05 reg Transit today because it's developed a fault. It would not allow me to access the engine control unit via OBD II, the first vehicle I've tried that hasn't.

Anyone know of any more that won't?.....

I tried a Focus with no luck. I wasn't sure if it was new enough for OBD-II though.

MK5 Fiesta (well it will let you scan a few engine bit's - providing the engine is running)

E46 BMW wont do anything

I've scanned a V reg Astra 2.0DTi, that worked fine. Also a 08 reg 1.6 Fiesta was fine......

Vag-com does not work with fords of a certain age (I've had problems with Mondeos and focus'. While they have an OBDII plug , I think they use a slightly different protocol.

I plugged my VCDS into an 05 reg Transit today because it's developed a fault. It would not allow me to access the engine control unit via OBD II, the first vehicle I've tried that hasn't.

Anyone know of any more that won't?.....

injectors, EGR valves, both very common faults on Tranny vans

Plugged a mates Vag-com into my Fabia today and it kept crashing claiming too many communication errors - any ideas?

VCDS doesn't work with older vauxhalls because they use a different protocol to VAG, have a look at the ross tech website I'm sure there is some info on different manufacturers on there.

It doesn't work with a Jaguar X-Type 2.0 Diesel. That's basically a Ford in any case so I'm not entirely surprised.....

I assume you need hex+can?

Is it a scan only, or has anyone changed things?

used it yesterday on a 55 plate corsa - worked fine & cleared the fault code. I'm using Hex+Can cable if that makes a difference