Locate the camshaft position sensor
Disconnect the sensor connector
Inspect the sensor, connector, and wiring for damage, corrosion, or loose pins
Check the vehicle service manual for sensor type and pinout
Set a multimeter to measure resistance
Test sensor resistance across the specified terminals
Compare the reading to manufacturer specifications
Set the multimeter to measure DC voltage
Reconnect the connector and backprobe the signal wire
Turn the ignition key to ON
Check for reference voltage and ground at the sensor
Crank or run the engine and monitor signal output
Use an oscilloscope to verify a clean switching waveform if available
Check for continuity between the sensor connector and ECU connector
Check for shorts to ground or power in the wiring
Scan for trouble codes with an OBD-II scanner
Clear codes and retest after repairs
Replace the sensor if readings are out of specification