View Full Version : Cruise Control Failing

04-30-2011, 12:45 AM
Hi guys,

I was doing some travel last week and noticed that my Cruise Control will engage and stay engaged at at 65mph or lower; and engage, but disengage, if I am running 70+ mph..? I'm not much of a CC fan, so should I address this or let it go..?


04-30-2011, 08:52 AM
If it works below a certain speed, but not above that speed.... you may have mis-matched tire sizes front & rear. What size tires do you have mounted?


04-30-2011, 09:25 PM
I had this problem - as Dave says there is something wrong with your wheels. Alignment/pressure/tyre size etc.

Mine occurred because the nearside wheel was buckled.

05-01-2011, 08:04 PM
Actually it stopped working all together yesterday.. I have Brabus 19's on it with 35 profile all around..

05-01-2011, 08:52 PM
I had trouble with my cruise control in my stock '92 400e. Though not identical to your symptoms of 70+, my cruise would give out suddenly and seemingly randomly, fast or slow. It would stop working for great lengths of time as well. I ignored it for over a year...I thought it was gone.

Here's my *really technical* contribution :-). The car went into the shop for other things (the car would sporadically but severely not start when warm). Troubleshooting included messing around with and merely removing and replacing the 6 (?) computers looking for anything as my car troubles were a great mystery. My cruise control started working again after one shop visit and has worked perfectly ever since. I had never even mentioned the problem to the mechanic because it wasn't a priority and it can be expensive. When it started working again there had been no new electronic parts installed, definitely no new computer, I'm sure. So maybe re-seat your modules?

Yeah...not much...but that's all I got! :-)

1992 400e 178,000

05-01-2011, 08:55 PM
Oh but I just read the alignment/pressure/tire size comment, which seems way more accurate than my goofball suggestion. My car would surely have had alignment and pressure/tires restored to normal operating standards. It was two years ago so I sort of forget the exact time line.

05-01-2011, 09:15 PM
Well if its the wheels I'm riding, guess I will have to do without CC, like my Brabus and not going back to stock 4sure.. Interesting observation about the modules, though. I think I might remove them and clean the contacts just for the sake of preventive maintenance.. I'll let ya'll know if I get anything unexpected and good because of it..