I was driving my
987.1
CS this weekend and had cruise control issues for the first time (it's an '06 with 114K miles). The problem occurred at normal interstate speeds. I would set the cruise, and it would function normally for awhile, and then it would cut off. I first thought I must have accidentally bumped the cruise control stalk and hit "cancel", or tapped the brake or clutch causing disengagement. However, after the second time this happened I took care that I wasn't the one causing this through errant motion.
I am not 100% if this was the case each time, but it seemed that it happened after going over a bump in the road (nothing major--e.g. transition from normal interstate to a bridge). At one point after cruise control cancelled I was not able to engage it again until I cut off and restarted the car. Anyone else have an issue like this? If it was due to a bump, could this be a faulty speed sensor causing PSM/ABS spoofing to kill the cruise? Seems like if that were the issue, though, there wouldn't be a problem with turning it back on again immediately without restarting the car.
Perhaps your clutch or brake switch are worn. If the spring mechanism is worn, a bump might make the contacts meet (or the reverse if an NC switch) causing the cruise control to cut off.
The clutch switch is a known weak point, you might start there. I'd pull it out of the car, hook up an ohmmeter, and jostle it around to see if it makes (or breaks).
Mine does the same thing and sometimes it won't engage when it is on. I have found that if I give the steering wheel a bump with my had it usually works. I'm guessing that something must be loose somewhere.
Second racegreg. Brake switch is know issue and with what you describe I would start there. It is easy to access and troubleshoot and inexpensive to repair.
Thanks for the leads, guys. I knew the clutch switch causes some owners starting issues, but the brake switch info is new to me. I'll check that out as it sounds like the quickest way to fix or narrow down the problem.
