A Camshaft Position - Timing Over-Advanced or System Performance (Bank 2)
The Powertrain Control Module (PCM) detected that the intake camshaft timing for Bank 2 is more advanced than commanded. This typically indicates a failure in the variable valve timing (VVT) system to properly regulate the camshaft position.
While the vehicle can usually still be driven, prolonged driving with incorrect camshaft timing can lead to poor performance, reduced fuel economy, and potential internal engine wear. It should be diagnosed and repaired soon.
Common symptoms
- Illuminated Check Engine Light
- Rough idle or stalling
- Reduced engine power and poor acceleration
- Decreased fuel economy
- Rattling noise from the engine, especially on startup
Likely causes
- Low engine oil level or dirty/sludged engine oil
- Faulty Variable Valve Timing (VVT) solenoid / Oil Control Valve (OCV) on Bank 2
- Clogged VVT oil passages or screens
- Defective camshaft position sensor or wiring issues
- Worn or damaged timing chain, tensioner, or phaser
What to check before replacing parts
Check the engine oil level and condition
Look for: Low oil level, heavily degraded oil, or sludge, which prevents proper hydraulic operation of the VVT system.
Inspect the Bank 2 VVT solenoid/OCV wiring and connector
Look for: Frayed wires, loose connections, or oil intrusion in the connector that could cause an open or short circuit.
Remove and inspect the Bank 2 VVT solenoid/OCV
Look for: Blocked screens, sludge buildup, or a stuck valve plunger that fails to move freely when bench-tested with 12 volts.
Monitor camshaft position data using an advanced scan tool
Look for: The actual Bank 2 camshaft angle remaining advanced and not matching the commanded angle during varying RPMs.
Inspect the timing chain and phaser assembly
Look for: A stretched timing chain, failed tensioner, or mechanically locked/damaged camshaft phaser on Bank 2.
This page explains the generic P0021 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
Gear guide: Best OBD2 ScannersRead this code yourself next time — from $20 Bluetooth dongles to bidirectional scan tools.Rather have a pro handle it? Find a vetted local mechanic.