cruise control wont work over 50mph 99 e300
 

just wondering what would cause this to happen. One day the cruise would just stop working over 50mph...sometimes 55mph. If I set it around 48 and bump the cruise stalk up 1 degree at a time it would just turn off on its own when i would hit that magic cutoff mph. Where can I look to fix this?

are all your tires the same size?

... and inflation?

And if all of that is good, you could check the output from your ABS sensors at the wheels.

you know what...i didnt think about it but I think the problem started when I put on my spare tire, and i havent had a chance to get my original fixed yet. Why would different tire sizes cause the cruise control to not work?

The ABS sensors detect different rotation/speeds of the wheels. This is an indication of tire slipping, it won't let the cruise set.

ahhh it all makes sense now...i also had a small problem where a couple of times the little exclamation point in the speedo would flash for no reason and slightly limit power.....looks like i need to get the spare off ASAP!

generally a good practice ;)

Im probably worse than most in that regard. damn -3 camber gives me all of 11k miles before i need new rear tires...

As a temporary measure, when you're driving, just press the ASR button on the console and that should keep it from reducing power. The triangle light will stay illuminated and may flash at times but it won't have any effect.

Your cruise may work again too... :)

I first discovered this "feature" when I mounted snow tires and the rears were slightly different sized than the front tires. The CC would cut out every time I'd start a turn on the highway. It drove me nuts until I realized it must be the tires because each spring when I put the all seasons back on, which were all the same size the problem would go away...now it is the first question I ask when someone says they are having problems with the CC on these cars.

I did something novel when I bought my first mercedes, I READ THE MANUAL. It's in there.

would have been nice if it came with one

Hehe...the manual which came with our new C300 is like 500 pages long. I don't think I will own the car for as long as it would take to read the whole thing :rolleyes:

My FIRST mercedes did have a manual you could actually read in about an hour and actually understand completely how the car operated. Now, the section on operating the radio is longer than the whole owner's manual was for my '74.