Circuit/System Description

The engine control module (ECM) uses the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor pulses to monitor the correlation between the crankshaft and camshaft position. The crankshaft reluctor wheel consists of a 60-tooth pattern with 2 teeth missing for a reference gap. Each tooth is evenly spaced 6 degrees apart, except for the reference gap. The camshaft reluctor wheel has 4 teeth, 2 narrow and 2 wide. The 4 trailing edges of each tooth are evenly spaced 90 camshaft degrees apart. As the crankshaft rotates with the CMP actuator in the home or parked position, the ECM expects CMP sensor pulses to occur 36 crankshaft degrees before top dead center (BTDC) at cylinder number 1, and every 90 camshaft degrees thereafter.