2008 Polaris Sportsman 500 EFI/X2/Touring/500 H.O. Service Manual, Page 131Get this manual
FUEL INJECTION MANIFOLD AIR PRESSURE SENSOR (MAP)
Operation Overview
Mounted on the throttle body intake, the manifold air pressure sensor (MAP) measures air passing and provides the ECU with the manifold pressure during engine operationThis allows the ECU to adjust the fueling according to actual engine load as well as identify which stroke is the intake strokeThe MAP sensor also provides the ECU with the ability to compensate for high altitude operation without any recalibrationDuring initial start-up, the ECU is in "waste sparkwaste fuel" mode until the MAP sensor sends negative pressure reading, indicating that the engine is on the intake strokeOnce this has been learned', the ECU will then monitor the MAP sensor and cease the initial start-up program
INTAKE AIR TEMPERATURE SENSOR (IAT)
Operation Overview
The intake air temperature sensor (IAT) is used to indicate charge air temperatures to the ECUMounted on the rear of the air box, the IAT sends varying voltage signal to the ECU in direct correlation to the ambient air temperatureThis 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