DTC Advanced Diagnostics: P0021 (3.0L Engine)
DTC P0021: Variable Valve Timing Control (VTC) A (Intake, Bank 2) System Timing Over-Advanced
General Description
The variable valve timing control (VTC) system controls the phase of the intake camshaft and exhaust camshaft. It uses oil pressure to operate VTC actuator A/B so the valve timing is optimized depending on driving conditions. The powertrain control module (PCM) monitors the difference between the target camshaft position and the actual camshaft position. If the difference between them is excessive for a certain time period, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 10 seconds or more |
| DTC Type | One drive cycle, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Elapsed time after VTC control started | 1 second | - |
| Engine speed [Engine Speed] | 530 RPM | - |
[ ]: HDS Parameter
Malfunction Threshold
Target camshaft position - (minus) actual camshaft position is less than -20° for at least 10 seconds.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- VTC oil control solenoid valve A (bank 2) failure
- VTC actuator A (bank 2) failure
- CMP sensor A (bank 2) failure
- Timing belt failure
Confirmation Procedure
Operating Condition
- Start the engine. Hold the engine speed [Engine Speed] at 3, 000 RPM without load (in P or N) until the radiator fan comes on.
- Drive the vehicle at a steady speed between 25 - 75 mph (40 - 120 km/h) for at least 10 seconds.
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, the freeze data, and the on-board snapshot are stored in the PCM memory.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.