Cruise control turning off & car accelerating unexpectedly

[PhastPhil]

I have 2 issues with my 2007 AM V8 coupe. While driving with the cruise control on, sometimes the cruise control disengages on it's on. The second issue is sometimes while driving with or without the cruise control, the car will unexpectedly accelerate with a surge in speed. Has anybody experienced these abnormal behaviors?

[john ryan]

Failure of the cruise control is typically a clock spring problem (the means by which the buttons on the steering wheel communicate with the car). Lots of Internet guidance and easy to change if you are half competent. Genuine clock springs are say £150 for a Land Rover D3, which is probably the same tech, but AM prices may be a bit (lot) higher. Get the codes read. Acceleration problem may indicate something else.

[stormblack]

This is interesting. I once had this with a B8 RS4- the car with cruise control activated would suddenly accelerate very aggressively on 3 occasions- very scary. I had Audi check the car out but they could never find out what was going on and denied there was a fault. Needless to say I moved the car on. I'd be interested to hear what is wrong with your cruise control.

[Genie Chaser]

The acceleration may be a cracked wheel bearing, may flag a fault for mechanical failure in the brake module if you have a code reader. This could be shutting the cruise down.

[dbs2000]

Disengaging could also be your brake sensor switch. If someone follows you they'll see you brake lights triggering randomly.
If it is this, the part is from a ford transit so not expensive.