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I finally have good, new tires on the car and took a nice cruise tonight to see the city lights. A few problems cropped up:
Cruise control doesn't work most of the time now. I am almost positive this has to do with the new tires after searching the forum for information. Can the computer be reprogrammed? I also got a Youcanic scanner to try to help with the AC system diagnostics and repairs. Would this give me some insight or allow for correction of the cruise control issue? I also washed out the wheel wells and sprayed off the shocks and struts, since I will replace those soon.
Moonroof stuck in the up position. I can hear the motor engaging, but the window will not close.
Many other issues, but the car is running very well and with the driveline flex discs, hanger bearing and tires replace, I begin to feel what this car will ride like. I have ordered supplies to complete a transmission and rear diff fluid change and hope to have that completed next week, along with an oil change (I already have that in hand).
I have a new Youcanic scanner that allows me to graph and compare the speed sensor readings of all 4 wheels. The difference at 45 mph, the rears are turning 2mph slower at 43 mph. That seems to be the cutoff point when the cruise control drops out. Even though this scanner is capable of changing tire sizes on many brands of cars, Mercedes is not one of them. I wonder if a dealer or someone with a STAR system can help? Otherwise, I have to spend more on tires which I really don't want to do.
EDIT: The more I research, the more I know that I will have to change the tires if I want cruise control back. The rear tires are way too big.
Last edited by tensleep80; Jul 9, 2023 at 07:39 AM.
I had a similar problem with the cruise control, in the workshop they made a mistake in the size of the tires and the cruise control did not work.
I put the appropriate measurements (+-2%) of margin with respect to the original measurements, and everything is fine.
Yes, I'm sure that's what my problem is. I'm going to look at some other issues first before I worry too much about that. It's driving great with these tires. It just won't be as nice on long road trips.
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