2006-2008 Polaris Snowmobiles FS/FST Service Manual., Page 105Get this manual
EFIIgnition Systems Wastegate Solenoid Pressure Testing
The wastegate solenoid allows the ECU to control the amount of boost pressure routed to the wastegate actuatorIn the event where power to the solenoid is lost, the solenoid defaults so that all of the boost pressure generated by the turbocharger is routed to the wastegate actuatorTo test the solenoid's function:
Wastegate Actuator Pressure Testing
The wastegate actuator is mechanical device that houses bellows, pre-load spring, and actuator armThe wastegate actuator is responsible for opening and closing the turbocharger's internal wastegate doorWhen the door is closed, all of the engine's exhaust gases are routed to the turbineThis action increases turbine speed and boost pressureWhen the door is opened, some exhaust gas is allowed immediately exit into the exhaust system, bypassing the turbineThis action decreases turbine speed and boost pressure