Thread: Cruise control does not always engage - ?suggestions

2006 TDV6 160k km

Some trips the cruise control engages perfectly well. Other trips the cruise control will not engage at all. The cruise control is more likely to engage when I have accelerated to the desired speed, taken foot off the accelerator pedal, then slowly applied more throttle and then pushed the switch on the steering wheel. If the car is being driven at a steady speed with the accelerator pedal held steady the cruise control is less likely to engage. These observations are true for 60, 80 and 100 km/h speeds. Turning ignition off and then back on may sometimes fix the failure of the cruise control to engage. When the cruise control is on it works perfectly. After the cruise control has been set, interrupted by braking, and the resume function is used, then the cruise control re-engages perfectly every time.

The rotary coupler was replaced by the dealer as part of a recall some years ago.

Any suggestions how this fault could be tracked down?

Could there be a sender unit problem at the accelerator pedal?

Is it just a worn switch on the steering wheel?

Is this a recognised fault for this model?

If yes, are there known software or hardware fixes?

Any suggestions would be gratefully received. Many thanks.

It is also pretty common for the micro-switches in the CC panel to fail. So brake switch, clock spring or cruise control switches would be the cause.