2008 Polaris Sportsman 500 EFI/X2/Touring/500 H.O. Service Manual, Page 132Get this manual
FUEL INJECTION IDLE AIR CONTROL (IAC)
General Information
The Idle Air Control (IAC) is used to stabilize the idle quality of the engine at cold start-up and after warm-up operationsMounted on the throttle body, the IAC contains stepper motor which receives varying voltage signal pulses from the ECUThese pulses determine the IAC plunger setting, thereby controlling the amount of air bypassing the closed throttle body for idle controlIf the IAC is disconnected or inoperative, it will remain at it's last operated position
THROTTLE POSITION SENSOR (TPS)
Operation Overview
The throttle position sensor (TPS), mounted to the throttle body, is used to indicate throttle plate angle to the ECUThe correct position of the throttle body idle stop is established and set at the factoryDo not loosen the throttle body idle stop or alter the stop position in any fashionIf the stop is repositioned, the entire throttle body assembly must be replacedMounted on the throttle body and operated directly off the end of the throttle shaft, the TPS works like rheostat, varying the voltage signal to the ECU in direct correlation to the angle of the throttle plateThis signal is processed by the ECU and compared to the internal pre-programmed maps to determine the required fuel and ignition settings for the amount of engine load