Complicated retrofit cruise control problem

[Z4coupebeaver]

The car is a 2007 (Aug 06 build) RHD Coupe. These cars are not pre-wired for CC according to BMW and the CC kit comes with an additional loom to graft into the wiring.

One end of the new loom (a blue cable) is supposed to connect into pin 4 on the black 26 pin plug on the DME control unit. Trouble is, there already is a violet cable in pin 4. I reported this to BMW who looked at the plug confirming that I had identified the correct pin and they explained that the car must have been pre-wired. Whilst this is incorrect for the model year, it is possible.

Looking under the dash, around the steering column, there is no corrosponding plug to fit into the CC switch. I could just go ahead and graft the wiring into the loom as described in the instructions, then remove the violet cable from pin 4 and connect the blue one but I guess I would be on my own if anything goes wrong.

The questions I'd like to ask are

Has anyone heard of a non CC coupe being pre-wired for CC?
Any ideas where I can look for the missing plug at the steering column end?
Does anyone know what the violet wire on pin 4 could be for?

I'm determined to get this resolved and even if nobody on here can help, at least this will be a pointer for others in the future.

 

[Z4coupebeaver]

First of all a big thanks to all of you who have pm'd me on this . None of the wiring diagrams were correct for my car though.

I eventually got Halliwell Jones to sort out the problem who after much dialogue with BMW. For some reason, on my car, pin 4 is wired to the gearbox control module. HJ say it could be because the car has the flappy paddle gearbox control. In any case they tell me they have wired the CC signal wire into the control box and it works well now.

BMW have recognised that their instructions in the CC retrofit kit are incomplete so have granted a warranty claim on the £230 labour charge this would have cost me otherwise.

It took a while to get there but a good result all round.

 

[gannet]

Glad you have a favourable outcome