Variable Boost Control Solenoid: Description and Operation

Turbocharger Pressure Vacuum Switching Valve Circuit Schematic:

The Turbocharger Pressure Vacuum Switching Valve (VSV), located on the RH side of the engine, allows the EFI Electronic Control Unit (ECU) to control Wastegate Actuator operation. Instead of spring tension only relieving actuator pressure and closing the Wastegate Valve, the ECU grounds the Turbocharger Pressure VSV and allows pressure to escape back to the intake tube, pre-turbo inlet. This system provides for faster Wastegate operation and allows for ECU control based on input from the Knock Control Sensor. For testing and diagnosis of the ECU and Knock Control Sensor, refer to COMPUTERIZED ENGINE CONTROLS. The Turbocharger Pressure VSV inputs the ECU through terminal TPC.