Continuous Variable Valve Timing (CVVT) system advances or
retards the valve timing of the intake and exhaust valve in accordance
with the ECM control signal which is calculated by the engine speed and
load.
By controlling CVVT, the valve over-lap or under-lap occurs,
which makes better fuel economy and reduces exhaust gases (NOx, HC) and
improves engine performance through reduction of pumping loss, internal
EGR effect, improvement of combustion stability, improvement of
volumetric efficiency, and increase of expansion work.
This system consist of
-the CVVT Oil Control Valve (OCV) which supplies the engine
oil to the cam phaser or runs out the engine oil from the cam phaser in
accordance with the ECM PWM (Pulse With Modulation) control signal,
- the CVVT Oil Temperature Sensor (OTS) which measures the engine oil temperature,
-and the Cam Phaser which varies the cam phase by using the hydraulic force of the engine oil.
The engine oil getting out of the CVVT oil control valve
varies the cam phase in the direction (Intake Advance/Exhaust Retard) or
opposite direction (Intake Retard/Exhaust Advance) of the engine
rotation by rotating the rotor connected with the camshaft inside the
cam phaser.
Inspection 1. Turn the ignition switch OFF. 2. Disconnect the PCSV connector. 3. Measure resistance between the PCSV terminals 1 and 2. 4. Check that the resistance is within the specification. Specification: ...
Inspection When the engine is shut off, the pressure change in the fuel tank by the ambient temperature is monitored by NVLD and when the engine is started, ECM judges whether there is a leak or not through the monitored data. If a leak is detected, ECM displays DTC P0455 or P0456. Process overview If ...