P0012

DTC P0011 Camshaft Position "A". Timing Over-Advanced or Stem Performance (Bank 1)
DTC P0012 Camshaft Position "A". Timing Over-Retarded (Bank 1)

DESCRIPTION

DTC Detection Condition:

The Variable Valve Timing (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, sent to the OCV, regulates the oil pressure applied to the VVT controller. Camshaft timing control is performed based on engine operation conditions such as intake air volume, throttle position and engine coolant temperature.

The ECM controls the OCV based on the signals output from several sensors. The VVT controller regulates the intake camshaft angle using oil pressure through the OCV. As a result, the relative position between the camshaft and the crankshaft is optimized. Also, the engine torque and fuel economy improve, and exhaust emissions decrease. The ECM detects the actual valve timing using signals from the camshaft position sensor and the crankshaft position sensor. The ECM performs feedback control and verifies target valve timing.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions (Part 1):

Typical Enabling Conditions (Part 2):

Typical Malfunction Thresholds:

The ECM optimizes the valve timing using the Variable Valve Timing (VVT) system to control the intake valve 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, sent to the OCV, regulates the oil pressure applied to the VVT controller. The VVT controller can advance or retard the intake valve camshaft.

Example: A DTC will be set if 1) the difference between the targeted and actual valve timing is more than 5 degrees of the camshaft angle (CA) and the condition continues for more than 4.5 seconds; or 2) the valve timing is no change.
Advanced cam DTCs are subject to "1 trip" detection logic.
Retarded cam DTCs are subject to "2 trip" detection logic.




If the difference between "target" and "actual" camshaft timing is larger than the specified value, the ECM operates the VVT actuator.
The ECM then monitors the camshaft timing change for 5 seconds.

Wiring Diagram:

Step 1-2:

Step 2(Continued)-3:

Step 4-7:

Step 8-11:

Step 1:

Step 1(Continued)-3:

Step 4-7:

Step 8-11:

INSPECTION PROCEDURE






HINT: Read freeze frame data using the intelligent tester or the OBD II scan tool. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.