Crankshaft Position Sensor

📖 YOUCANIC Automotive Glossary

The crankshaft position sensor (CKP) reads a toothed reluctor wheel on the crankshaft to determine rotational position and speed — one of the ECU’s most critical inputs for ignition timing, injection timing, and RPM calculation. A gap in the tooth pattern provides the angular reference point. CKP sensors are magnetic (variable reluctance, AC signal) or Hall-effect (digital square wave at all speeds).

CKP failure can cause intermittent stalling, no-start (engine cranks but will not fire), rough running, and misfires. DTCs: P0335 (Circuit Malfunction), P0336 (Range/Performance), P0339 (Intermittent). Complete failure typically means no-start because the ECU cannot determine engine position. Test magnetic sensors by measuring resistance (200-2000 ohms) and AC voltage while cranking. Common failure causes: heat degradation and damaged reluctor teeth.