Intake Camshaft Position Timing Over-Advanced (Bank 2)
The P0021 code means the vehicle's onboard diagnostic system has detected: Intake Camshaft Position Timing Over-Advanced (Bank 2). This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $50 - $3,000 (oil change vs. solenoid vs. phaser/chain replacement; a full timing chain, guide, and tensioner job on chain-stretch-prone engines like the GM 3.6L V6 and Nissan VQ commonly runs $1,800-$3,000+)
Common Misconceptions / Fact Check
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Commonly claimedA camshaft timing code like P0021 means the timing chain or phasers are worn out and you are facing a $2,000+ repair.
VerifiedUsually not. The variable-valve-timing phaser is actuated by oil pressure, so the most common triggers are low or dirty engine oil and a stuck or clogged VVT solenoid. Start with an oil-and-filter change using the exact specified viscosity, then test the solenoid (often a $40-$90 part) before condemning the timing chain. The expensive chain/phaser job is the exception, not the default.
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Common Symptoms
- Check Engine Light illuminated
- Rough idle and engine hesitation
- Hard starting, especially when warm
- Decreased fuel economy
- Possible engine knocking or pinging
Probable Causes (Ranked by Likelihood)
- Low or dirty engine oil Very High
- Failed intake VVT solenoid (bank 2) High
- Stretched timing chain on bank 2 Moderate
- Stuck camshaft phaser in the advanced position Moderate
- Clogged oil passages to the camshaft phaser Low
Step-by-Step Diagnostic Procedure
-
Check engine oil level on the dipstick and inspect oil condition. Dark, gritty oil can cause VVT malfunctions. Perform an oil change with the manufacturer-recommended viscosity.
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Using a scan tool, monitor intake camshaft position (bank 2) at idle. Compare actual position to desired. A deviation of more than 5 degrees over-advanced confirms the issue.
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Remove and inspect the bank 2 intake VVT solenoid. Check the oil screen for debris. Measure solenoid resistance (6-13 ohms typical).
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Check timing chain tension on bank 2. Excessive slack or a rattling noise on startup indicates a stretched chain or worn tensioner.
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Verify the camshaft phaser is not mechanically stuck by commanding the VVT solenoid on and off while monitoring camshaft position changes on the scan tool.
Common Fixes by Vehicle
What techs usually find when diagnosing P0021 on specific vehicles — tap your vehicle for the fix and the exact part:
2007-2015 Nissan Altima/Maxima 3.5L VQ35 moderate DIY
Intake camshaft timing over-advanced on bank 2 is most often caused by dirty oil or a stuck variable valve timing (VVT/VTC) solenoid. Start with an oil and filter change using the correct viscosity — sludge is the #1 cause. If it persists, replace the bank 2 intake camshaft position actuator solenoid before suspecting the timing chain.
Labor: 1-2 hours2005-2019 Nissan Pathfinder/Frontier/Xterra 4.0L VQ40DE Moderate DIY
Bank 2 is the firewall-side head on the VQ40. The code is most often dirty oil or a stuck intake VTC (variable timing control) solenoid, not the timing chain. Change the oil and filter with the correct grade first, then replace the bank 2 intake camshaft position / VTC solenoid. Only suspect the timing chain or VTC actuator (cam sprocket) if you hear a cold-start rattle that fades after a few seconds.
Labor: 1-2 hours2007-2017 Chevrolet Traverse/GMC Acadia/Cadillac CTS 3.6L V6 (LLT/LFX) Moderate DIY
The 3.6L V6 is known for both VVT actuator solenoid sticking and timing chain stretch. Start with an oil change on the Dexos spec and replace the bank 2 intake cam actuator solenoid. Important: if there is a rattle on cold start or you also see P0008/P0016/P0017 (correlation codes), the timing chains and guides are the real fix -- the solenoid alone will not clear it. GM issued TSBs covering early-build 3.6L chain wear.
Labor: 1-2 hours2007-2017 Ford Edge/Explorer/Taurus/F-150 3.5L & 3.7L V6 (Cyclone) Moderate DIY
On the Cyclone V6, P0021 is usually a sticking variable cam timing (VCT) solenoid or a worn cam phaser, aggravated by extended oil-change intervals. Change the oil and replace the bank 2 intake VCT solenoid first. A persistent cold-start 'diesel-like' rattle points to a failed phaser, which is a bigger job -- do not just keep replacing solenoids if the rattle is present.
Labor: 1-2 hoursFrequently Asked Questions
Can I drive with code P0021?
You can drive short distances to a repair shop, but the engine may idle rough and have reduced power. Prolonged driving with over-advanced timing can increase exhaust temperatures and stress engine components.
Is P0021 the same as P0011 but for bank 2?
Yes, exactly. P0011 indicates intake camshaft over-advanced on bank 1, while P0021 is the same condition on bank 2. The diagnostic approach is identical but applied to the opposite bank of the engine.
Can using the wrong oil cause P0021?
Yes. The VVT system is sensitive to oil viscosity and quality. Using oil that is too thick, too thin, or of poor quality can prevent proper actuator operation. Always use the viscosity and specification recommended by your vehicle manufacturer.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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