Monitor Description

The ECM optimizes the intake valve timing using the Variable Valve Timing (VVT) system to control the intake camshaft. The VVT system includes the ECM, cam timing oil control solenoid assembly, camshaft timing gear bolt (camshaft timing oil control valve assembly [for intake camshaft]) and camshaft timing gear assembly. The ECM sends a target duty-cycle control signal to the cam timing oil control solenoid assembly. The camshaft timing gear bolt (camshaft timing oil control valve assembly [for intake camshaft]) is operated to control the oil pressure supplied to the camshaft timing gear assembly based on this signal. The camshaft timing gear assembly can advance or retard the intake camshaft.

If the difference between the target and actual intake valve timing is large, and changes in the actual intake valve timing are small, the ECM interprets this as the camshaft timing gear assembly stuck malfunction and stores a DTC.

1. Example:
2. A DTC is stored when the following conditions are met:
   1. It takes 5 seconds or more to change the valve timing by 5°CA.
   2. After the above condition is met, the cam timing oil control solenoid assembly is forcibly activated for 9.5 seconds.

These DTCs indicate that the camshaft timing gear assembly cannot operate properly due to a camshaft timing gear bolt (camshaft timing oil control valve assembly [for intake camshaft]) malfunction or the presence of foreign matter in the camshaft timing gear bolt (camshaft timing oil control valve assembly [for intake camshaft]).