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P0027 — Exhaust Valve Control Solenoid Circuit Rangeperformance Bank 1

Generic OBD-II · all makesPowertrain (engine & transmission)

Code P0027 indicates that the engine control module has detected a performance or range issue with the exhaust valve control solenoid on Bank 1. This solenoid regulates oil flow to the cam phaser to adjust exhaust valve timing; a failure here prevents the engine from optimizing combustion and emissions.

Symptoms

What causes it — most likely first

1. Contaminated Engine Oil

Oil sludge or debris can clog the small passages within the solenoid, preventing it from moving the oil required to adjust valve timing.

2. Faulty Exhaust Solenoid

The solenoid may have suffered an internal electrical failure or mechanical sticking, rendering it unable to actuate.

3. Low Oil Level or Pressure

Insufficient oil volume or low hydraulic pressure prevents the solenoid from effectively shifting the camshaft position.

4. Wiring or Connector Damage

Corroded pins, frayed wires, or loose connections can interrupt the signal between the PCM and the solenoid.

5. Worn Cam Phaser

Internal wear or failure of the cam phaser mechanism can cause the timing to remain out of range regardless of solenoid operation.

6. PCM Failure

A fault in the engine control module's driver circuit is rare but may result in incorrect signaling to the solenoid.

How it's diagnosed

  1. Check the engine oil level and inspect the oil for excessive sludge or contamination.
  2. Inspect the solenoid electrical connector for corrosion, moisture, or loose pins.
  3. Measure the solenoid's electrical resistance using a multimeter to verify it is within factory specifications.
  4. Perform a solenoid actuation test using a scan tool or external 12V power source to check for mechanical movement.
  5. Verify oil pressure at the VVT gallery using a mechanical pressure gauge to ensure the phaser is receiving enough flow.
  6. Inspect the camshaft and phaser for mechanical wear or debris if the solenoid is functioning correctly.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationSAE generic — identical on every make
Related codesP0020 — Camshaft Position Actuator Control CirP0021 — Camshaft Position Timing Over AdvancP0022 — Camshaft Position Timing Over RetardP0023 — B Camshaft Position Actuator Control CP0024 — B Camshaft Position Timing Over AdvaP0025 — B Camshaft Position Timing Over Reta

Frequently asked

Can a simple oil change fix P0027?

Yes, if the code was caused by oil sludge or incorrect oil viscosity blocking the solenoid, a fresh oil change and filter can sometimes resolve the issue.

Do I need to replace my engine computer (PCM) for this code?

It is very unlikely. P0027 is almost always caused by oil contamination, a failed solenoid, or mechanical wear. The PCM should only be considered after all sensors and wiring are verified.

Will the car run if I ignore this code?

The vehicle will typically remain drivable, but it will operate in a 'limp' or default timing mode, leading to poor fuel economy and potential emissions failure.