Error code
OBD2 P0021
OBD2P0021
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.
What it means
'A' Camshaft Position - Timing Over-Advanced or System Performance.
Severity
moderateCan drive, but performance issues and potential engine damage may occur.
Summary
P0021 indicates that the 'A' camshaft position sensor on bank 2 is timing over-advanced or has system performance issues.
Symptoms
- Loss of gas mileage
- Engine stalling
- Check engine light
Common Causes
- Poor oil maintenance leading to carbon buildup and filter blockage in the VCT/VVT solenoid.
- Use of low-quality oil causing premature wear or failure of the camshaft timing system.
Diagnosis
- Use a multimeter to check the resistance of the camshaft position sensor terminals.
- Pin test continuity in the wiring harness between the valve solenoid and PCM/ECM.
- Check all engine grounds and clean/tighten harness terminals.
Fixes
- Replace the camshaft position sensor or VCT/VVT solenoid.
FAQ
What is causing my P0021 code?
The most common cause is poor oil maintenance leading to carbon buildup and filter blockage in the VCT/VVT system.
How can I prevent future issues with this code?
Use high-quality oil, maintain regular engine cleaning, and ensure proper lubrication of the camshaft timing system.
Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.
More OBD2 codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0005Fuel Shutoff Valve 'A' Control Circuit/Open
- P0006Fuel Shutoff Valve 'A' Control Circuit Low
- P0007Fuel Shutoff Valve 'A' Control Circuit High
- P0008Engine Position System Performance
- P0009Engine Position System Performance
- P0010'A' Camshaft Position Actuator Circuit
- P0011'A' Camshaft Position - Timing Over-Advanced or System Performance
- P0012'A' Camshaft Position - Timing Over-Retarded