Note. For circuit reference, see WIRING DIAGRAMS - 4.3L article.
Circuit Description
Crankshaft Position (CKP) sensor provides VCM with reference pulse input. VCM uses CKP input to determine ignition spark timing for each cylinder. Once VCM calculates ignition timing, it sends a signal to ignition coil module on Ignition Control (IC) circuit.
Conditions for setting DTC
- Engine speed less than 250 RPM.
- EST is enabled.