The function diagram for the VGT actuator includes the following:
• VGT actuator
• Electronic Control Module (ECM)
• Accelerator Pedal Position sensor and Idle Validation Switch (APS/IVS)
• Barometric Absolute Pressure (BAP) sensor
• Camshaft Position (CMP) sensor
• Crankshaft Position (CKP) sensor
• Engine Coolant Temperature (ECT) sensor
• Exhaust Gas Recirculation (EGR)
• Engine Oil Temperature (EOT) sensor
• Exhaust Back Pressure (EBP) sensor
• Injection Control Pressure (ICP) sensor
• Injection Pressure Regulator (IPR)
• Manifold Absolute Pressure (MAP) sensor
• Manifold Air Temperature (MAT) sensor
• ENGINE lamp (amber)
Function
The VGT actuator is a control module that contains a microchip and a DC motor. The VGT actuator is located below the turbocharger. The microchip operates a DC motor which rotates a crank lever controlling the vane position in the turbine housing.
The position of the vanes is based off the pulse width modulated signal sent from the ECM.
Actuator control for the vane position is achieved by setting a pulse width modulated signal from the ECM in response to the following:
• Engine speed
• Desired fuel quantity
• Boost (manifold air pressure)
• Exhaust back pressure and altitude
