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.
Fig. 38: DTC P0011 Camshaft Position "A" - Timing Over-Advanced Or System Performance (Bank 1) -
Communication Diagram
DTC DETECTION CONDITION AND TROUBLE AREA
DTC
Code
DTC Detection Condition
Trouble Area
P0011
P0021
Valve timing is not adjusted in valve timing advance range
(1 trip detection logic)
Valve timing
OCV for intake camshaft
OCV filter
Intake camshaft timing gear
assembly
2008 Toyota Tundra
2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra