System Components

ENGINE MANAGEMENT SYSTEM – V8

DESCRIPTION AND OPERATION 18-2-43

Variable Camshaft Control Electronic Control
The following describes the electronic control of the VCC system.

Electronic Control
The engine control module is responsible for activating a VCC variable position solenoid valve based on EMS 
program mapping. The activation parameters are influenced by the following input signals:

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Engine speed 

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Load (intake air mass)

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Engine temperature

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Camshaft position.

Mechanical Control
The position of the solenoid valve directs the hydraulic flow of engine oil. The controlled oil flow acts on the mechanical 
components of VCC system to position the camshaft.

The hydraulic engine oil flow is directed through advance or retard activation oil ports by the VCC solenoid. Each port 
exits into a sealed chamber on the opposite sides of a control piston.

In its default position the oil flow is directed to the rear surface of the piston. This pulls the helical gear forward and 
maintains the retarded valve timing position.

When the oil flow is directed to the front surface of the piston, the oil pushes the helical gear in the opposite direction 
which rotates the matched helical gearing connected to the camshaft.

The angled teeth of the helical gears cause the pushing movement to be converted into a rotational movement. The 
rotational movement is added to the turning of the camshaft providing the variable camshaft positioning.

System Components
The V8 VCC components include the following for each cylinder bank: 

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Cylinder heads with oil ports for VCC

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VCC transmission with sprockets

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Oil distribution flange

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Oil check valve

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PWM controlled solenoid valve

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Camshaft position impulse wheel.