Crankshaft Position Sensor Wiring Diagram: No RPM, No Spark, No Start

If the scan tool shows no engine RPM while cranking, the crankshaft position sensor circuit becomes one of the first places to test. The engine computer may not command spark or injector pulse without that signal.

The wiring diagram shows whether the sensor is a two-wire magnetic sensor or a three-wire Hall-effect sensor, and where the signal reaches the PCM.

A two-wire sensor creates its own AC signal. A three-wire sensor usually needs power, ground, and a signal path. The wrong test method can create a false diagnosis.

Use the diagram to identify terminal order, reference voltage, sensor ground, shielded wiring, and PCM connector pin before probing the circuit.

Crank sensor wiring often runs near the engine block, starter, exhaust, or transmission. Heat, oil, vibration, and previous repairs can damage insulation or terminals.

If the fault is intermittent, inspect connector tension and harness routing while monitoring RPM signal or scope pattern.

Sensor-side tests are useful, but PCM-side tests prove whether the signal reaches the engine computer. ECU pinout and connector view pages help locate the correct terminal.

If the signal is present at the sensor but missing at the PCM, the fault is likely between the sensor connector and module connector.