Error code

OBD2 P0390

OBD2P0390
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

Camshaft Position Sensor 'B' Circuit.

Severity

moderateCan drive, but performance will be affected.

Summary

P0390 indicates a malfunction in the camshaft position sensor B circuit for bank 2 of your vehicle's engine.

Symptoms

  • Hesitation upon acceleration
  • General lack of engine performance
  • Diminished fuel efficiency
  • Overheated catalytic converter due to timing issues
  • Spark detonation (backfire) when decelerating
  • Spark knock (pinging) when accelerating

Common Causes

  • Defective camshaft sensor or crankshaft sensor
  • Open or shorted wiring to the camshaft sensor
  • Corroded or fluid-soaked connector/camshaft sensor
  • Faulty PCM or PCM programming error

Diagnosis

  1. Perform a visual inspection of all system-related wiring harnesses and connectors.
  2. Test voltage and ground signals at the camshaft sensor using a digital volt/ohmmeter (DVOM).
  3. Disconnect and test the camshaft sensor for resistance values.
  4. Use an oscilloscope to observe waveform patterns near the sensor and PCM connector.

Fixes

  • Replace defective sensors or wiring as needed.

FAQ

What does P0390 mean?

P0390 indicates a malfunction in the camshaft position sensor B circuit for bank 2 of your vehicle's engine.

How do I diagnose P0390?

Diagnose by checking wiring, connectors, and sensors using diagnostic tools like DVOM and oscilloscope.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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