2.9L - Description And Operation

DESCRIPTION 

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The right bank Variable Valve Timing (VVT) phaser assembly is managed by the primary Powertrain Control Module (PCM) via two VVT solenoids that regulate the flow of oil conveyed within the chambers of the phase assemblies.

Similarly to the right bank, the VVT phaser assemblies of the left bank are managed by the secondary PCM via two other VVT solenoid valves that regulate the flow of oil conveyed within the chambers of the phase assemblies assemblies.

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In conditions of key OFF, the phase assemblies are in their resting position:

• Intake camshaft phase assemblies: maximum delay position.
• Exhaust camshaft phase assemblies: maximum advance position.

When the phase assemblies are at or near their respective resting position, the valves do not cross.

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OPERATION 

The moment the engine is started, the oil pressure rises until it reaches operating values, and subsequently the lock pins of the phase assemblies are deactivated allowing the latter to move to their resting position.

The movement of the phase assemblies is allowed by the engine oil going under pressure in the chambers bound by the rotor walls and the outer body of the assemblies themselves.

The engine control module activates both assemblies in each bank using a specific mapping based on revolutions and engine load. Using the phase sensors of the camshafts, the PCM can control the VVT in a closed loop.

The VVT solenoid valves distribute the oil in function by the Pulse-Width Modulated (PWM) input command they receive from the PCM.

Courtesy of CHRYSLER GROUP, LLC