Speedometer in my GMC van just started to go about twice the actual speed indicated, with now a maximum van speed of about 45 MPH and then some governor kicks in and shuts down motor, transmission and gas pedal until the van goes below the 120 MPH mark again and then resumes. I cannot go over about 45 MPH maximum speed now. The odometer appears to follow this new problem by following the speedometer speed as well about double the mileage. Any help is greatly appreciated. I don;t know where to start.
Saturday, November 10th, 2012 AT 10:22 PM