P0012

DTC P0012 Camshaft Position "A" - Timing Over-Retarded (Bank 1)

DESCRIPTION

DTC Detection Condition:

The Variable Valve Timing (VVT) system includes the ECM, 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.

HINT: If DTC P0011 or P0012 is present, check the VVT (Variable Valve Timing) system.

MONITOR DESCRIPTION

Monitor Strategy (Part 1):

Monitor Strategy (Part 2):

Typical Enabling Conditions:

Typical Malfunction Thresholds:

The ECM optimizes the 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 actual intake valve timing are small, the ECM interprets this as the VVT controller stuck malfunction and sets a DTC.

Example:
A DTC will be set if 1) the difference between the target and actual valve timings is more than 5° of the camshaft angle (CA) and the condition continues for more than 4.5 seconds; or 2) the OCV is forcibly activated 12 times or more.

Advanced cam DTC is subject to "1 trip" detection logic.

Retarded cam DTC is subject to "2 trip" detection logic.

Wiring Diagram:

Step 1:

Step 1(Continued)-3:

Step 3(Continued)-5:

Step 6-7:

INSPECTION PROCEDURE

NOTE: DTC P0011 or P0012 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: Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.