Vibe FWD L4-1.8L VIN 8 (2004)
2 - Vane Wheel
3 - Intake Camshaft
4 - CMP Actuator Housing
The CMP actuator assembly has an outer housing (4) that is driven by the engine timing chain. Inside the assembly is a wheel (2) with fixed vanes that is
attached to the intake camshaft (3). The CMP actuator assembly also contains a lock pin (1) that prevents movement between the outer housing and the
wheel vane assembly. The lock pin is released by oil pressure before any movement in the CMP actuator assembly takes place.
Camshaft Position (CMP) Actuator Solenoid Valve
1 - Spool Valve
2 - Solenoid Plunger
3 - Solenoid Coil
4 - Oil Return During Retard
5 - Oil Supply
6 - Oil Return During Advance
7 - Oil Supply to Camshaft Position Actuator for Advance
8 - Oil Supply to Camshaft Position Actuator for Retard
The CMP actuator solenoid valve directs the oil flow that controls the camshaft phase movement. The PCM commands the CMP solenoid to move the
solenoid plunger (2) and spool valve (1) until oil flows from the advance passage (7) or the retard passage (8). In most operating conditions the opposite
oil return passage is open at the same time as the oil supply passage.
Operation
The PCM operates the CMP actuator solenoid valve by pulse width modulation (PWM) of the solenoid coil. The higher the PWM duty cycle, the larger
the change in camshaft timing. Oil pressure that is applied to the advance side of the fixed vanes will rotate the camshaft in a clockwise direction. The
clockwise movement of the camshaft will advance the timing up to a maximum of 21 degrees. When oil pressure is applied to the return side of the
vanes, the camshaft will rotate counterclockwise until returning to 0 degrees.
CMP Actuator System Advance
1 - Vane Wheel
2 - CMP Actuator Housing, part of CMP actuator assembly
3 - Intake Camshaft Gear, part of CMP actuator assembly
4 - Intake Camshaft
5 - Advance Side Oil Passage, applying pressure
6 - CMP Actuator Solenoid Valve
7 - Retard Side Oil Passage, relieving pressure
