Speedometer Calibration: Calibration

The vehicle speed buffer is matched to the final drive and tire size of each vehicle. If final drive or tire size has been changed for any reason, buffer must also be changed. Speed buffer is an internal part of the Digital Ratio Adapter Controller (DRAC) and is not serviceable. If buffer is faulty, DRAC must be replaced. If buffer is faulty and is not changed, speedometer/odometer reading will be inaccurate. An incorrect buffer signal will also affect anti-lock brakes, engine and cruise control system operation.