C 2500 Truck 2WD V8-454 7.4L (1988)
Vehicle Speed Sensor: Component Tests and General Diagnostics
Test C
C: PROGRAMMER CLIP TEST
1. Find the rear tire radius by measuring the distance in inches from the center of either rear tire to the ground. This number is R.
2. Find the axle ratio. This number is A.
3. Calculate the vehicle pulses per mile using the illustrated formula.