2006-2008 Polaris Snowmobiles FS/FST Service Manual., Page 91Get this manual
EFIIgnition Systems Wastegate Solenoid Pulse Valve Circuit (FST Only)
The wastegate solenoid pulse valve allows the ECU to control the amount of boost pressure within the induction systemBoost control is accomplished by pulsing the valve at different frequencies depending on the amount of boost pressure within the induction systemIf the ECU determines that the targeted boost pressure has been obtained, the ECU will trigger the pulse valve so that certain level of compressor pressure is routed to the wastegate actuatorDoing so activates the wastegate so that proportion of exhaust gas bypasses the turbineIn the event that power to the wastegate solenoid is lost, the solenoid defaults so that all of the compressor pressure is routed to the wastegate actuatorWhen this occurs, maximum boost pressure will be limited to the wastegate's internal spring popoff pressure of6.5 lbs(413448 milliBAR) The wastegate solenoid is located on the front of the air box next to the turbocharger