K 2500 Truck 4WD V8-454 7.4L VIN J SFI (1997)
Crankshaft Position Sensor: Testing and Inspection
Crankshaft Position (CKP) Sensor Diagnosis
The crankshaft position sensor provides a signal through the ignition control module which the VCM uses as reference to calculate RPM and crankshaft
position. Refer to Enhanced Ignition System / Diagnostic Tables.