Engine

P0027 — Exhaust Camshaft Timing Control Range/Performance (Bank 1)

Severity: medium Drive with care, to a shop

What P0027 means

The PCM compares the commanded exhaust camshaft position on bank 1 with the actual position reported by the camshaft and crankshaft sensors. An oil control solenoid (VVT solenoid) directs oil pressure to the cam phaser to shift timing. P0027 sets when the cam does not reach or hold the target angle within the expected range.

Symptoms

  • Check Engine light on
  • Rough or unstable idle
  • Sluggish acceleration, reduced power
  • Higher fuel consumption
  • Possible emissions test failure
  • Rattling or ticking on startup (if phaser is failing)

Possible causes

  1. Faulty exhaust cam timing (VVT) oil control solenoid
  2. Damaged wiring or corroded solenoid connector
  3. Low, dirty, or wrong-viscosity engine oil
  4. Clogged solenoid screen or oil passages
  5. Worn or sticking camshaft phaser
  6. Incorrect cam timing (stretched chain, misaligned marks)
  7. Rarely, a PCM fault or outdated software

How to diagnose

  1. Scan all codes and freeze-frame data; look for related cam or crank sensor codes
  2. Check oil level, condition, and viscosity against the manufacturer spec
  3. Inspect the solenoid connector and harness for chafing, corrosion, or oil intrusion
  4. Test solenoid coil resistance and verify power and control signal from the PCM
  5. Remove the solenoid, inspect its screen for debris, and check that it moves when energized
  6. Run a scan tool VVT active test and compare commanded versus actual cam angle
  7. Check oil pressure and verify cam timing (look for chain stretch)
  8. If needed, inspect the phaser for play or sticking

Common fixes

  • Change the oil and filter with the specified grade
  • Clean or replace the VVT solenoid
  • Repair the solenoid wiring or connector
  • Replace the cam phaser or timing chain if worn
  • Update PCM software or replace the PCM (rare)

Questions and answers

Can I drive with a P0027 code?

Briefly and carefully, until it is repaired. If the engine knocks, misfires, or oil pressure drops, stop driving, or you risk engine damage.

Can old oil alone cause P0027?

Yes, it is a common cause. The phaser runs on oil pressure, and dirty or overly thick oil can clog the solenoid screen and slow the response. An oil and filter change is a cheap first step.

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.