Engine

P0023 — Camshaft Position Actuator "B" Circuit Malfunction (Bank 2)

Severity: medium Drive with care, to a shop

What P0023 means

The PCM adjusts valve timing with VVT solenoids that direct oil pressure to the camshaft phasers. P0023 sets when the PCM detects a problem in the electrical circuit of the "B" camshaft actuator on bank 2, such as an open, a short or out-of-range resistance. "B" usually refers to the exhaust cam, but the naming varies by engine.

Symptoms

  • Check Engine light on
  • Rough or fluctuating idle
  • Reduced power and sluggish acceleration
  • Higher fuel consumption
  • Rattle from the phaser at startup
  • Possible hard starting or stalling at idle

Possible causes

  1. Failed bank 2 VVT solenoid (oil control valve)
  2. Open or shorted wiring, or corroded or damaged connector
  3. Low, dirty or wrong-grade engine oil
  4. Clogged solenoid screen or oil passages
  5. Sticking cam phaser or stretched timing chain
  6. Internal PCM fault (rare)

How to diagnose

  1. Scan for all codes and freeze frame data, and look for other VVT or cam sensor codes
  2. Check oil level and condition and confirm it meets the manufacturer's spec
  3. Inspect the bank 2 solenoid connector and harness for oil, chafing and corrosion
  4. Measure solenoid coil resistance and compare with spec
  5. Check for power, ground or the control signal at the connector
  6. Command the solenoid with a scan tool and watch the response
  7. Compare commanded and actual cam angle in live data
  8. If deviation persists, check timing marks, chain condition and the phaser

Common fixes

  • Change the oil and filter with the specified oil
  • Replace the bank 2 VVT solenoid, cleaning the screen and bore first
  • Repair the wiring or connector
  • Replace the cam phaser or timing chain if mechanically worn
  • Reflash or replace the PCM only after ruling out everything else

Questions and answers

What does P0023 mean?

It is a circuit fault in the "B" camshaft position actuator on bank 2, part of the variable valve timing system. The PCM sees an electrical problem or a mismatch in control.

Can I drive with P0023?

Briefly and gently, yes, but expect reduced power and economy. If the cause is oil or a mechanical problem, driving on can lead to costly engine damage.

What most often causes P0023?

Most often a failed VVT solenoid or damaged wiring or connector. Also check oil level and quality.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.