Driving down the M1 today southbound near junction 23A with the cruise control set at 50mph, dreaded road works.  Ran across a small but deep pothole and the cruise control deactivated.  At first I did not cotton on as to what had happened other than the car was slowing, after selecting the reset the car resumed the correct speed.  I assume that maybe a relay maybe bounced and switched it off? Is that likely?

I suspect that if the ABS or traction control etc electronics detects sudden unequal wheel rotation speed, it will instantly disable the cruise as a safety precaution. (it could be the start of a skid)

 

Jim

Edited 12 August, 20178 yr by muddyjim

If the brake light flashes, because it's too finely adjusted, it'll trip the cc .

It shouldn't be too hard to adjust.

(if you back up to a wall and touch the brake pedal you should be able to see the lights and confirm if it's too fine)

I have had this happen a few times at the same place, front drivers side wheel drops into a low grid and CC turns off.

It's a safety feature as you could be incapacitated and drifting off the road.

Thanks guys.  It's the first time it's happened so I'll probably just go with the flow and see if it happens again.  Having experienced it once I'll not be quite so surprised if and when it happens again. Interestingly, as RickT says it's happened to him, it's probably a 'feature' rather than a fault?

Indeed, seems to be related to the traction control as I've had it happen to me on ice. I'm sure a wheel dropping into a hole and changing rotation speed unexpectedly will activate the traction control in the same way.

All cars with traction control/esp (of all brands) do this automatically. Wheelspin disables cruise control; and dropping into a deep enough pothole is perceived by the sensors as wheelspin.

I had the same recently in the road works on the M42 - minor pothole and cruise deactivated. I'd assumed (as above) this is normal behaviour

Mystery solved. thanks guys.