P0021 - A Camshaft Position - Timing Over-Advanced or System Performance Bank 2
P0021 is a generic powertrain diagnostic trouble code indicating A Camshaft Position - Timing Over-Advanced or System Performance Bank 2. It relates to the Fuel & Air Metering and Auxiliary Emission Controls system.
DTC Breakdown (SAE J2012)
| System | Powertrain (P) |
| Type | Generic |
| Subsystem | Fuel & Air Metering and Auxiliary Emission Controls |
| Fault Index | 21 |
| Standard | SAE J2012 / ISO 15031-6 |
What does diagnostic code P0021 mean?
The engine computer logged P0021 after detecting a Variable Valve Timing (VVT) issue with the Bank 2 intake camshaft, indicating a over-advanced fault.
Severity Level & Driveability Details
Severity: High
Low engine oil can cause severe internal engine damage. Timing chain wear can cause timing to jump, bending valves on interference engines.
Common Symptoms of P0021
- Rattling engine noise from the front timing cover near Bank 2.
- Rough engine idle and stalling.
- Noticeable loss of engine power under load.
- Check engine light illuminated.
Typical Causes for P0021
- VVT oil control solenoid stuck open for the Bank 2 intake camshaft.
- Camshaft phaser gear mechanical lock pin failing to engage on Bank 2.
- Low or contaminated engine oil restricting phaser movement.
- PCM VVT circuit or software calibration issue.
Diagnostic and Troubleshooting Steps
Check oil level and cleanliness first. Use a scan tool to command the VVT solenoid; the engine should stumble at idle if the solenoid operates. Test solenoid resistance using a multimeter.
Typical Repairs and Fixes
- Replacing the Bank 2 intake VVT solenoid.
- Replacing the Bank 2 intake camshaft phaser assembly.
- Performing an engine oil and filter change.
- Checking and updating PCM software.
Sensor Location & Parts Involved
The VVT solenoid is mounted on the cylinder head near the camshaft gear, while the cam phaser is on the end of the camshaft itself.
Clearing Code & Recurrence
Reset codes with a scan tool and perform a road test to verify VVT solenoid operation.
Emissions & Smog Inspection Impact
Incorrect valve timing leads to incomplete combustion and elevated tailpipe emissions.
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Related Diagnostic Codes
Sources & References
This diagnostic guide is compiled and verified against the following authority sources:
- NHTSA TSB Bulletins
- EPA OBD regulations
Frequently Asked Questions about P0021
What does the Bank 2 intake camshaft timing over-advanced code P0021 mean?
The engine computer logged P0021 after detecting a Variable Valve Timing (VVT) issue with the Bank 2 intake camshaft, indicating a over-advanced fault.
Is it safe to drive with the Bank 2 intake camshaft timing over-advanced code P0021 active?
No, VVT timing faults can damage internal engine parts if left unresolved.
How much does it cost to repair a Bank 2 intake camshaft timing over-advanced code P0021 fault?
An oil change is $50-$80. Solenoid replacement runs $150-$350. Replacing the timing chain is a major mechanical job costing $1,200-$2,500.
What are the common causes of the Bank 2 intake camshaft timing over-advanced code P0021?
Trigger conditions for the Bank 2 intake camshaft timing over-advanced code P0021 include: VVT oil control solenoid stuck open for the Bank 2 intake camshaft., Camshaft phaser gear mechanical lock pin failing to engage on Bank 2., Low or contaminated engine oil restricting phaser movement..
Can I clear the check engine light for Bank 2 intake camshaft timing over-advanced code P0021?
Reset codes with a scan tool and perform a road test to verify VVT solenoid operation.
Will the Bank 2 intake camshaft timing over-advanced code P0021 cause an inspection failure?
Incorrect valve timing leads to incomplete combustion and elevated tailpipe emissions.