MONITOR DESCRIPTION
- The ECM optimizes the exhaust valve timing using the Variable Valve Timing (VVT) system to control the exhaust camshaft. The 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. The VVT controller can advance or retard the exhaust camshaft.
- If the difference between the target and actual exhaust valve timing is large, and changes in actual exhaust 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 "A" and "B" are met:
- It takes 5 seconds or more to change the valve timing by 5锟斤拷CA (Condition "A").
- After the above condition is met, the camshaft timing oil control valve assembly is forcibly activated 10 seconds (Condition "B").
- DTCs P0014 and P0024 (advanced camshaft timing) are subject to 2 trip detection logic.
- DTCs P0015 and P0025 (retarded camshaft timing) are subject to 1 trip detection logic.
- These DTCs indicate that the VVT controller cannot operate properly due to camshaft timing oil control valve assembly malfunctions or the
presence of foreign objects in the camshaft timing oil control valve assembly.
- The monitor will not run unless the following conditions are met:
- The engine is warm (the engine coolant temperature is 75锟斤拷C [167锟斤拷F] or more).
- The vehicle has been driven at more than 40 mph (64 km/h) for 3 minutes.
- The engine has idled for 3 minutes.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
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