P0369

Symptoms

• Intermittent rough idle that comes and goes
• hesitation or stumble during acceleration
• hard starting or a no-start condition
• engine stalling
• reduced engine performance and loss of power
• lower fuel efficiency
• engine misfires
• backfiring during deceleration
• pinging/spark knock during acceleration
• possible overheated catalytic converter from timing issues
• Check Engine Light illuminated.

Probable causes

• 1) Faulty camshaft position sensor B (internal failure from heat, vibration, or age) - the most common cause. 2) Damaged sensor wiring or connector: broken wires
• corrosion
• loose terminals
• or oil-soaked connectors causing intermittent contact. 3) Poor ground: compromised ground strap or corroded engine-block bolt introducing resistance. 4) Severely dirty engine oil affecting sensor operation. 5) Timing chain/belt stretch or wear causing the cam signal to be out of sync. 6) Sticking VVT solenoids or phasers moving cam position unpredictably. 7) Faulty PCM or programming error (rare).

Diagnostic steps

1. Connect a scan tool, document all stored codes and freeze frame data.
2. Visually inspect the sensor wiring harness and connectors for oil/coolant contamination, corrosion, chafing, and loose terminals.
3. Verify reference voltage and ground at the sensor connector against manufacturer specifications.
4. Disconnect the sensor and test its internal resistance against specification.
5. Monitor the sensor signal with an oscilloscope while the engine runs, looking for spikes, glitches, or missing signal blocks.
6. Perform a wiggle test on the wiring and connectors while monitoring the signal to expose intermittent connections.
7. Compare waveforms at the sensor connector versus the PCM connector to isolate an open or shorted circuit.
8. Check engine oil level and condition; inspect timing chain/belt and VVT components if correlation issues are suspected.
9. If the waveform is good throughout the circuit and all else passes, suspect the PCM.