V70 2.4 L5-2.4L VIN 61 B5244S (2001)
Variable Valve Timing Solenoid: Description and Operation
Camshaft reset valve (Continuous variable valve timing (CVVT))
The camshaft reset valve controls the oil flow to the continuous variable valve timing (CVVT) unit. The valve consists of an electro-magnetic valve
with a spring-loaded piston. There are slits in the piston which channel the engine lubricating oil to different channels in the continuous variable valve
timing (CVVT) unit by moving the piston in the reset valve. The continuous variable valve timing (CWT) unit turns the camshaft (the cam timing
changes). The direction in which the camshaft turns depends on the chamber in the CWT unit which is supplied with oil (pressure).
The system relay supplies the reset valve with voltage. The valve is grounded (control stage) in the engine control module (ECM). When the valve is
grounded using a pulse width modulation (PWM) signal, the oil flow in the valve can be controlled to the different chambers in the continuous
variable valve timing (CVVT) unit at variable rates. This allow the angle of the camshaft to be changed precisely and smoothly.
The engine control module (ECM) has diagnostics for the reset valve. The value of the reset valve can be read using VADIS.
Only cars of model year 2000 and later have continuous variable valve timing (CVVT). The valve is on the cylinder head above the camshaft with
camshaft control.
