Chevrolet Impala Speedometer Calibration

This page contains information on how to roll back or calibrate speedometer on Chevrolet Impala (2002) manually. You will need our TachoSoft Mileage Calculator and programmer. 

In Chevrolet dash the mileage is stored in 68HC912B32. To power up the circuit board use 12 volts to A1 + A8 + and A4 is your - ground.