Hi everyone,

I have a 2002 S430 whose cruise control works PERFECTLY at 51 MPH or less. However, once reaching 52 MPH or higher, the LED bars around the speedometer blink and the cruise control disengages.

It doesn't matter if I accelerate to any speed 52 or above (let's say 70 MPH for example), then try to engage the cruise control, or if I engage the cruise control at say 40 MPH then use the cruise control lever to try to accelerate to 70. It ALWAYS disengages at 52, the bars around the speedometer blink and the cruise control disengages.

The tire sizes all match and the tire pressure is dead on. Again all functions (accelerate, decelerate, resume, etc.) work PERFECTLY at the lower speeds 100 % of the time. And 100% of the time, I get the same result above 52 MPH.

It all worked perfectly until about a week ago. I first noticed a problem when I engaged it on an entrace ramp, and used the cruise accelerate feature to get up to speed, then had to immediately toggle to decelerate to accomodate traffic. I braked during the decelerate so I could merge with traffic. I believe that's the last time it worked correctly (at speeds over 52 MPH anyway).

Did I stumble on some cruise control lever sequence that set a "top limit" for the cruise control feature accidentally? If so, how do I fix it?

Thanks in advance! I'm certainly stumped on this one!