P0021

A Camshaft Position - Timing Over-Advanced or System Performance Bank 2

Q: Is it safe to drive with P0021?

Only briefly. The engine may run rough or stall, and a real timing fault can stress the valvetrain. Get it looked at promptly rather than driving on it.

Q: Can I just clear P0021?

It will come straight back unless the cause is fixed. Because low or dirty oil is the usual trigger, an oil change is worth doing before clearing.

Variable valve timing Generic OBD-II High

What it means

P0021 means the variable valve timing on bank 2 is over-advanced, or the cam timing isn't responding the way the ECM commands. The system runs on oil pressure through a solenoid and phaser, so low or dirty oil is a frequent cause. Expect rough running and reduced power until it's sorted.

High

Can I keep driving? Limp along only — the engine may run rough or stall and timing faults can stress the valvetrain, so drive as little as possible until it's fixed.

Real-world scan data

Seen in

187

scans in the past year

Found in

<0.1%

of scans

0.1%

of scans that found faults

Appears alongside · share of P0021 scans

P0011in 37.4% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Rough idle, hesitation, or occasional stalling
Reduced power and sluggish acceleration
Rattle or whine from the front of the engine on some vehicles

Common causes

Most likely first

Low or dirty engine oil — the most common trigger; the VVT phaser runs on oil pressureLikely
Stuck or clogged camshaft oil-control (VVT) solenoid on bank 2Common
Faulty camshaft position sensor or wiringCommon
Worn camshaft phaser/actuator on bank 2Less often
Stretched timing chain or jumped timing causing the cam to sit over-advancedLess often
Rarely, a faulty ECMLess often

How to diagnose & fix

Work through it in order

Check the oil level and condition first — top up or change the oil with the correct grade if it's low, dirty, or overdue.
Read freeze-frame data and inspect the bank 2 VVT solenoid; remove and clean it, checking for sludge and debris.
Test the camshaft position sensor and its wiring for the correct signal.
If oil and solenoid check out, inspect the phaser and verify timing-chain condition and cam/crank correlation.
Clear the code and re-test after each step to confirm the fix.

FAQ

Quick answers

Is it safe to drive with P0021?+

Only briefly. The engine may run rough or stall, and a real timing fault can stress the valvetrain. Get it looked at promptly rather than driving on it.

Can I just clear P0021?+

It will come straight back unless the cause is fixed. Because low or dirty oil is the usual trigger, an oil change is worth doing before clearing.

Read & clear P0021 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX