HINT
DTC P0016 or P0018 is output when foreign objects in engine oil are caught in some parts of the system. These codes will remain
stored even if the system returns to normal after a short time. These foreign objects may then be captured by the oil filter, thus
eliminating the source of the problem.
B -- REPLACE ECM See: Powertrain Management/Computers and Control Systems/Engine Control Module/Service and
Repair/Removal
A -- END
From 08/2009
2GR-FE ENGINE CONTROL: SFI SYSTEM: P0016,P0018: Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A)
P0018 - Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor A)
DESCRIPTION
The Variable Valve Timing (VVT) system includes the ECM, camshaft timing oil control valve assembly and VVT controller. The ECM sends a
target duty-cycle control signal to the camshaft timing oil control valve assembly. This control signal regulates the oil pressure supplied to the VVT
controller. Camshaft timing control is performed according to engine operating conditions such as intake air volume, throttle valve position and
engine coolant temperature. The ECM controls the camshaft timing oil control valve assembly, based on the signals transmitted from several sensors.
The VVT controller regulates the intake camshaft angle using oil pressure through the camshaft timing oil control valve assembly. 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
The ECM optimizes the valve timing by using the Variable Valve Timing (VVT) system to control the intake camshaft. The VVT system includes
the ECM, the camshaft timing oil control valve assembly and the VVT controller.
The ECM sends a target duty-cycle control signal to the camshaft timing oil control valve assembly. This control signal regulates the oil pressure
applied to the VVT controller. The VVT controller can advance or retard the intake camshaft. The ECM calibrates the intake valve timing by setting
the intake camshaft to the most retarded angle while the engine is idling. The ECM closes the camshaft timing oil control valve assembly to retard
the cam. The ECM stores this value as the VVT learning value. When the difference between the target and actual intake valve timing is 5锟斤拷CA
(crankshaft angle) or less, the ECM stores it.
If the VVT learning value matches the following conditions, the ECM determines the existence of a malfunction in the VVT system, and sets the
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