Engine oil level too low, or oil that doesn't meet the manufacturer's requirements (RepairPal). Failed camshaft variable timing solenoid, for example stuck open (both sources). Variable valve timing actuator failure, or continuous oil flow to the VCT piston chamber (RepairPal; OBD-Codes.com). Incorrect camshaft timing or a worn timing chain (both sources). Wiring problems in the intake timing control solenoid circuit (OBD-Codes.com).

Change the engine oil and filter with the correct oil specification (RepairPal's listed common repair). Replace a failed bank 2 variable timing solenoid or VVT actuator (both sources). Correct the cam timing or replace a worn timing chain and related parts (both sources). Repair damaged solenoid circuit wiring (OBD-Codes.com).

P0021🔧 Engine / variable valve timingStop and fix promptly

P0021: "A" Camshaft Timing Over-Advanced, Bank 2 (Meaning, Causes, Fixes)

Q: What does P0021 mean?

P0021 means the engine computer has found that the 'A' camshaft on bank 2 is more advanced than it should be, or the cam timing system isn't performing as expected. Common causes are low or incorrect engine oil, a failed variable valve timing solenoid or actuator, and incorrect cam timing such as a worn timing chain. Many modern engines use variable valve timing (VVT, also called VCT) to shift the camshaft for better power and efficiency. The engine computer (PCM/ECM) compares the camshaft position sensor signal with the crankshaft signal to check that the cam is where it commanded. OBD-Codes.com says P0021 sets when the cam timing is above a set limit (over-advanced), and that it is basically the same as P0011 except for bank 2. RepairPal describes it more broadly: the PCM sets P0021 when the camshaft is not in the proper position relative to the crankshaft. Bank 2 is the side of a V6 or V8 engine that does not have cylinder 1, so inline four-cylinder engines don't set P0021. The 'A' camshaft is the intake, left or front camshaft. P0022 is the over-retarded version, P0020 is the circuit code for the same camshaft, and Nissan calls this code 'Camshaft variable timing control - Bank 2 - performance' (OBD-Codes.com). The two sources also weigh the causes differently: RepairPal puts low or incorrect engine oil first, while OBD-Codes.com doesn't mention oil. OBD-Codes.com calls P0021 a mechanical fault of the VCT unit that doesn't need electrical diagnosis, yet it also lists solenoid wiring problems as a cause, so a quick wiring check is still sensible.

Q: Can I keep driving with P0021?

Stop and fix promptly. Get it diagnosed promptly. RepairPal rates P0021 Urgent, meaning it can lead to significant problems and should be checked right away. OBD-Codes.com gives no formal rating but says the code most likely brings hard starting, poor idle and/or stalling. Cam timing that is out of place can also point to low or wrong engine oil or a worn timing chain, so it's worth checking the oil level before driving far.

Reviewed 2026-10-23 · Based on 2 cited source(s)

What P0021 means

Many modern engines use variable valve timing (VVT, also called VCT) to shift the camshaft for better power and efficiency. The engine computer (PCM/ECM) compares the camshaft position sensor signal with the crankshaft signal to check that the cam is where it commanded. OBD-Codes.com says P0021 sets when the cam timing is above a set limit (over-advanced), and that it is basically the same as P0011 except for bank 2. RepairPal describes it more broadly: the PCM sets P0021 when the camshaft is not in the proper position relative to the crankshaft. Bank 2 is the side of a V6 or V8 engine that does not have cylinder 1, so inline four-cylinder engines don't set P0021. The 'A' camshaft is the intake, left or front camshaft. P0022 is the over-retarded version, P0020 is the circuit code for the same camshaft, and Nissan calls this code 'Camshaft variable timing control - Bank 2 - performance' (OBD-Codes.com). The two sources also weigh the causes differently: RepairPal puts low or incorrect engine oil first, while OBD-Codes.com doesn't mention oil. OBD-Codes.com calls P0021 a mechanical fault of the VCT unit that doesn't need electrical diagnosis, yet it also lists solenoid wiring problems as a cause, so a quick wiring check is still sensible.

Severity: can I keep driving?

Stop and fix promptly

Get it diagnosed promptly. RepairPal rates P0021 Urgent, meaning it can lead to significant problems and should be checked right away. OBD-Codes.com gives no formal rating but says the code most likely brings hard starting, poor idle and/or stalling. Cam timing that is out of place can also point to low or wrong engine oil or a worn timing chain, so it's worth checking the oil level before driving far.

Common symptoms

Check engine light on
Hard starting (OBD-Codes.com)
Poor idle (OBD-Codes.com)
Stalling (OBD-Codes.com)
Decreased engine performance (RepairPal)
Increased fuel consumption (RepairPal)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Engine oil level too low, or oil that doesn't meet the manufacturer's requirements (RepairPal)
Failed camshaft variable timing solenoid, for example stuck open (both sources)
Variable valve timing actuator failure, or continuous oil flow to the VCT piston chamber (RepairPal; OBD-Codes.com)
Incorrect camshaft timing or a worn timing chain (both sources)
Wiring problems in the intake timing control solenoid circuit (OBD-Codes.com)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Read all stored codes and freeze-frame data. If P0021 shows up with bank 1 cam timing codes such as P0011, or with cam or crank correlation codes, note them all before replacing parts.
Check the engine oil level and condition and confirm it is the grade the manufacturer specifies. RepairPal lists low or incorrect oil as causes and an oil and filter change as the common repair.
Inspect the bank 2 VVT/VCT solenoid connector and wiring for damage, oil in the connector or loose pins.
Clear the code after any oil service and see whether it returns before buying parts.

Typical fixes

Change the engine oil and filter with the correct oil specification (RepairPal's listed common repair)
Replace a failed bank 2 variable timing solenoid or VVT actuator (both sources)
Correct the cam timing or replace a worn timing chain and related parts (both sources)
Repair damaged solenoid circuit wiring (OBD-Codes.com)

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

The oil is correct and full but the code keeps coming back
The VCT unit needs component tests from the vehicle-specific repair manual or with a scan tool, which OBD-Codes.com says dealer techs can do
The engine rattles at startup, runs badly or stalls
Cam timing or the timing chain needs to be checked, which usually means opening up the front of the engine

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I drive with P0021?

Only gently and get it checked soon. RepairPal rates P0021 Urgent, and OBD-Codes.com says it can cause hard starting, poor idle or stalling.

Can an oil change fix P0021?

Sometimes. RepairPal lists low oil and oil that doesn't meet the manufacturer's spec as causes and an oil and filter change as the common repair, because the timing system runs on oil pressure. If the code returns, the solenoid, actuator or timing chain need checking.

What's the difference between P0021 and P0011?

They mean the same thing on different sides of the engine. OBD-Codes.com says P0021 is basically P0011 for bank 2 instead of bank 1.

Why does my four-cylinder not have bank 2?

Bank 2 only exists on engines with two cylinder banks, such as V6 and V8 engines. Inline engines have a single bank, so they use the bank 1 codes like P0011.

How much does it cost to fix P0021?

Neither source gives a repair cost for P0021. It ranges from an oil change to a new timing solenoid or a timing chain job, so get it diagnosed first.

Sources

Last reviewed 2026-10-23. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.