P0021 P0021 OBD-II: "A" Camshaft Position - Timing Over-Advanced or System
What P0021 means for you
Both sources align on a high severity.
Symptoms
- The Check Engine Light is activated when the P0021 code is present.
- You might not experience immediate physical symptoms, but the engine may idle normally at first and then hesitate during acceleration.
- Stalling can occur when coming to a complete stop due to an improper air-fuel mixture.
- Increased fuel consumption is likely as the camshaft positions are not optimal, leading to higher emissions.
- Starting the engine may become difficult at times, and a rough engine operation can be experienced.
- In severe cases, a knocking or rattling noise may be heard from the engine compartment, indicating the need for immediate inspection.
Common causes
- One primary cause of the P0021 code is the camshaft being set to a more advanced position than specified by the ECM.
- Conversely, the camshaft may also be retarded beyond the expected timing.
- A clogged or malfunctioning oil control valve (OCV) can trigger this code as well.
- Using incorrect or low viscosity oil, or having consistently dirty oil can also lead to this issue.
- Failure of the camshaft variable valve timing (VVT) control solenoid may prevent it from functioning correctly.
- Lastly, if the camshaft phaser becomes stuck in the advanced position, it is likely to set off the P0021 code.
Tune it yourself
Buy a tuning tool and start remapping P0021 for your customers. We provide the accessories and the file. You keep the profit.
Start tuning
Or send us your ECU
Prefer we handle it? Send your ECU straight to us and we’ll fix it for you.
Send your ECUWhat this code means
The P0021 code indicates that the Engine Control Module (ECM) has detected that the intake camshaft on bank two is positioned more advanced than the ECM's specifications. This situation arises in modern engines equipped with variable valve timing systems, which enhance performance and fuel efficiency by managing the timing of valve openings and closings. The ECM relies on signals from both the camshaft and crankshaft position sensors to ensure proper engine timing. If the camshaft is misaligned, the ECM will flag the P0021 code.
Frequently asked questions
It is not advisable to continue driving with a P0021 code due to the risk of engine damage and increased emissions.
The cost to repair the P0021 code can vary significantly based on the underlying issue, but expect to pay for diagnostic time and potential parts replacement.
Symptoms of a P0021 code include decreased engine performance, increased fuel consumption, and potential engine stalling.
