CRUISE CONTROL FAILS AT 55MPH & OVER - DEALERS DISAGREE ON CAUSE - ANY INSIGHTS?
Last year, I bought my 2000 CLK 320 convertible with 48K miles from the original owner (California) & didn't discover until I was driving it home to Illinois that the cruise control won't stay set at speeds between 55 mph & 100 MPH (works fine at less than 55 & over 100).
The Mercedes Dealer Service rep in Hoffman Estates, Il. said that it was due to the wrong size TIRES (no mention of wheel size) & once I put the recommended tire size on, it will correct itself.
Currently, my car has 18" OEM chrome AMG wheels & tire sizes:
FRONT = 245/40R 18 93H
REAR = 265/35Z R 18 93w
Needless to say, it will cost me a pretty penny to change all 4 wheels & all 4 tires, so I got a second opinion.
The Mercedes Dealer Service rep in Naperville, Il. said that he sees Mercedes cars will all sorts of oversized wheels come into his shop all the time with no cruise control issues, & that the cruise control is "self-adjusting", so tire size shouldn't affect it - but the only way to find out for sure if the other service rep was right or wrong is to have them switch my car's wheels with another car that has the 205 55 R16 tires & 16" wheels (probably off a loaner car)& take it for a test drive & test the cruise control.
That "test" will cost me about $300.00.
I'd like to think that modern automotive computers & technology could do a better job pinpointing problems than what I've gotten from local Mercedes dealership service departments.
Has anyone else experienced a problem like this with their Mercedes cruise control? If so, do you know what caused the problem or how to fix it?
Does anyone know if or how such a 2000 Mercedes CLK 320 convertible cruise control issue could be more precisely and directly diagnosed & corrected?
I'm open to any & all ideas that a diminutive woman with no automotive skills (me) can research or try that won't cost me hundreds or thousands of dollars for experimental work that has no guaranteed results.
Thanks