OBD Codes

P0021

Intake Camshaft Position Timing Over-Advanced (Bank 2)

Moderatevariable valve

Overview

The P0021 diagnostic trouble code indicates a intake camshaft position timing over-advanced (bank 2) condition. This code relates to the variable valve timing (VVT) system, which adjusts camshaft timing for optimal performance across the engine's RPM range. VVT issues often stem from oil quality or flow problems and can cause rough idle, poor performance, and decreased fuel economy.

Symptoms

  • Check Engine Light (MIL) illuminated
  • Rough or unstable idle
  • Reduced engine performance
  • Poor fuel economy

Common Causes

  • Dirty or low engine oil
  • Faulty VVT solenoid/actuator (oil control valve)
  • Incorrect oil viscosity for the engine
  • Failed VVT phaser/actuator

Diagnosis Steps

  1. 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
  2. 2Check engine oil level and condition; change oil if dirty or incorrect viscosity
  3. 3Test the VVT solenoid (oil control valve) with a multimeter
  4. 4Inspect the VVT solenoid screen/filter for debris or sludge
  5. 5Monitor camshaft position sensor data using scan tool live data

Estimated Repair Cost

$150$1,000

Cost varies by vehicle, location, and repair shop. Includes parts and labor.

Commonly Affected Vehicles

Honda Civic (VTEC)Ford Escape (EcoBoost)Hyundai Sonata (CVVT)Toyota Camry (2.5L)

Related Codes

More Variable Valve Codes

Frequently Asked Questions

Yes, dirty or low-quality engine oil is one of the leading causes of VVT system problems. Oil sludge can clog the VVT solenoid screen and oil passages, preventing proper cam timing adjustment.