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Camshaft Position Actuator and Solenoid Valve Description Valvetrain Camshaft - part 2

Rating:
Duringnormal engine operation, and based on performance requirements, theECM may adjust camshaft timing, as required, within a range from7-degrees advanced to 45-degreesretard.

CMP System Lubrication Flow and Actuator Operation

Camshaft Position Actuator and Solenoid Valve Description Valvetrain Camshaft

Oil enters the camshaft at the second main bearingjournal-(1).Oil travels through the camshaft into the CMP actuator valvecheck ball-(2) and filter-(3).Oil exits the valve and travels through the internal passagesof the camshaft-(4).Oil exits the camshaft and enters the actuator oil entryports.Oil travels through the actuator and is directed back intothe valve-(5).Valve spool position directs oil to the advance or retardpassages of the actuator.

The valve may also, under certain conditions, be positionedin a neutral position with no flow to either the advance or retardpassages of the actuator.

Camshaft Position Actuator and Solenoid Valve Description Valvetrain Camshaft

Oil flows from the camshaft into the valveinlet-(3) through the internal check ball andfilter.Oil exits the valve-(2) and travels within theinternal passages of the camshaft into the entryports-(7) of the actuator.The center oil groove of the actuator is pressurized and oilreenters the valve-(1).Valve spool position directs oil out of the valveadvance-(5) or retard-(4) ports to theactuator.

The valve may also, under certain conditions, be positionedin a neutral position with no flow to either the advance or retardpassages of the actuator.

Camshaft Position Actuator and Solenoid Valve Description Valvetrain Camshaft

Pressurized oil enters the retard cavities-(2) ofthe actuator and moves the park pin-(3) from the lockedposition.As pressure increases within the retardcavities-(2), the rotor and camshaft rotate counterclockwise retarding valve timing.As the duty cycle decreases, the spool is repositioned andoil is sent to the advance cavities-(1), rotating therotor and camshaft clockwise, advancing valve timing.With a 0-percent duty cycle signal to the magnet,the spool is positioned in the fully extended position and there isfull flow to the advance cavities of the actuator. As duty cycleincreases to near 50-percent, flow to the advancecavities is decreased.With a 50-percent duty cycle, the spool ispositioned neutral, with no flow to either the advance and retardcavities.With a 51–100-percent duty cycle, thespool is positioned to provide oil flow to retard cavities. As theduty cycle increases, the flow to retard cavities increases.With a 100-percent duty cycle, there is full flowto the retard cavities of the actuator.The above duty cycle percentage values are only a guideline,as the actual duty cycle values may vary based on engine oiltemperature, solenoid magnet coil temperature, magnet coilresistance, and other specifics.CMP Actuator Park Position Verification

Camshaft Position Actuator and Solenoid Valve Description Valvetrain Camshaft

The CMP actuator can be visually inspected to determine ifthe tension spring has returned the reluctor wheel and rotor to thepark position.

With the reluctor wheel returned to the proper parkedposition, the edge of the notched area of the wheel-(2)aligns with the marking-(1) on the camshaftsprocket.

CMP Actuator Handling Safety

Camshaft Position Actuator and Solenoid Valve Description Valvetrain Camshaft

Warning:Refer toCamshaft Position Actuator Removal and Installation Warning.

Camshaft Position Actuator and Solenoid Valve Description Valvetrain Camshaft

Install tie wrap-(1) to retain the reluctor wheelto the sprocket. The reluctor wheel is mounted to the actuator bodywith 3-roll pins.

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