V50 AWD L5-2.5L Turbo VIN 68 B5254T3 (2005)
The camshaft reset valve controls the oil flow to the CVVT unit (camshaft pulley).
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 the
CVVT unit by moving the piston in the reset valve. The continuous variable valve timing (CVVT) unit turns the camshaft (the camshaft timing changes).
The direction in which the camshaft turns depends on the chamber in the CVVT 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 regulated 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) can diagnose the camshaft reset valve.
The valve is on the cylinder head above the camshaft with camshaft control.
Camshaft Control (CVVT)
Camshaft Control (CVVT)
When the camshaft (A) is set at the factory, it is aligned with the position of the crankshaft (B). The position of the camshaft in relation to the crankshaft
is designated the camshaft 0 position. During camshaft (CVVT) control, the 0 position of the camshaft is advanced so that the opening and closing of the
intake and exhaust valves can be changed to match the camshaft. Engine performance can be increased, idle quality increased and emissions reduced by
regulating the camshaft timing changes.
There are diagnostics for this function.
Knock Control
Knock Control
