W124 1994 E320 Cruise Control Problems
 

Any ideas? The cruise control engages and accelerates on the stalk up to 40 miles an hour and then switches off. Above 40, it will not engage at all. Amplifier time? Why 40?

Thanks.

I know some times that is caused by uneven tire diameters. Not sure if that is true for all years though. Does your car have ASR?

Tire size and inflation is possible. Also, do you get an occasional ABS light?

Very interesting... It just dawned on me that I noticed the problem AFTER the car had a tire replaced under its road hazard warranty. It hadnt been driven in a few days, and, I really didnt think about it. The tire was replaced with an identical Michelin, but with of course no miles. It was put on the front drivers side.

So.. this now begs the question... what should I do short of putting another new tire on the front??

Thanks for the replies!

Try it on the rear if your car is a non-ASR car. The idea is that the non-ASR cars have a wheel-speed sensor on each front wheel, but on the rear it is on the differential so the speed error will be divided by two. If an ASR car, you have four speed-sensors and it might not work.

Contact the tire dealer who installed the tire, tell him that you can't have a tire mismatch and see if they will cut you a really good deal on a second tire, .. which should help but no guarantees, ... hate to make it three more.

Like magic.... Moved tire to rear, cruise works flawlessly. It is hard to believe that the system is THAT sensitive. The other tires are not very old, maybe six months. That was a very inexpensive repair.. the kind i like.

Thanks again for the help.