P0021

DTC P0011 Camshaft Position "A" - Timing Over-Advanced or System Performance (Bank 1)
DTC P0012 Camshaft Position "A" - Timing Over-Retarded (Bank 1)
DTC P0021 Camshaft Position "A" - Timing Over-Advanced or System Performance (Bank 2)
DTC P0022 Camshaft Position "A" - Timing Over-Retarded (Bank 2)

DESCRIPTION

DTC Detection Condition:

The VVT system includes the ECM, Oil Control Valve (OCV) and VVT controller. The ECM sends a target duty-cycle control signal to the OCV. This control signal regulates the oil pressure supplied to the VVT controller. Camshaft timing control is performed according to engine operating conditions such as the intake air volume, throttle valve position and engine coolant temperature. The ECM controls the OCV, based on the signals transmitted by several sensors. The VVT controller regulates the intake camshaft angle using oil pressure through the OCV. As a result, the relative positions of the camshaft and crankshaft are optimized, the engine torque and fuel economy improve, and the exhaust emissions decrease under overall driving conditions. The ECM detects the actual intake valve timing using signals from the camshaft and crankshaft position sensors, and performs feedback control. This is how the target intake valve timing is verified by the ECM.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

The ECM optimizes the intake valve timing using the VVT (Variable Valve Timing) system to control the intake camshaft. The VVT system includes the ECM, the Oil Control Valve (OCV) and the VVT controller. The ECM sends a target duty-cycle control signal to the OCV. This control signal regulates the oil pressure supplied to the VVT controller. The VVT controller can advance or retard the intake camshaft.

If the difference between the target and actual intake valve timings is large, and changes in the actual intake valve timing are small, the ECM interprets this as the VVT controller stuck malfunction and sets a DTC.

Example: A DTC is set when the following conditions 1, 2 and 3 are met:

1. The difference between the target and actual intake valve timing is more than 5 °CA (Crankshaft Angle) and the condition continues for more than 4.5 seconds.
2. It takes 5 seconds or more to change the valve timing by 5 °CA.
3. After conditions 1 and 2 are met, the OCV is forcibly activated 63 times or more.

DTC P0011 and P0021 (Advanced Cam Timing) are subject to 1 trip detection logic.
DTC P0012 and P0022 (Retarded Cam Timing) are subject to 2 trip detection logic.

These DTCs indicate that the VVT controller cannot operate properly due to OCV malfunctions or the presence of foreign objects in the OCV.
The monitor will run if all of the following conditions are met:
- The engine is warm (the engine coolant temperature is 75 °C [167 °F] or more).
- The vehicle has been driven at more than 64 km/h (40 mph) for 3 minutes.
- The engine has idled for 3 minutes.

TYPICAL MALFUNCTION THRESHOLDS

Typical Malfunction Thresholds:

If the difference between the target and actual camshaft timings is greater than the specified value, the ECM operates the VVT actuator.

Then, the ECM monitors the camshaft timing change for 10 seconds.

Wiring Diagram:

Step 1-2:

Step 2(Contuined)-3:

Step 4-5:

Step 5(Contuined)-8:

Step 8(Contuined):

INSPECTION PROCEDURE

HINT: DTC P0011, P0012, P0021 or P0022 may be set when foreign objects in the engine oil are caught in some parts of the system. The DTC will remain set even if the system returns to normal after a short time. Foreign objects are filtered out by the oil filter.

HINT:
- If DTC P0011 or P0012 is displayed, check the left bank VVT system for intake camshaft circuit (for bank 1).
- Bank 1 refers to the bank that includes No. 1 cylinder.
- If DTC P0021 or P0022 is displayed, check the right bank VVT system for intake camshaft circuit (for bank 2).
- Bank 2 refers to the bank that does not include No. 1 cylinder.
- Read freeze frame data using the intelligent tester or Techstream. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.