2008 Polaris Sportsman 500 EFI/X2/Touring/500 H.O. Service Manual, Page 125Get this manual
FUEL INJECTION ELECTRONIC CONTROL UNIT (ECU)
Operation Overview
The ECU is the brain or central processing computer of the entire EFI fuelignition management systemDuring operation, sensors continuously gather data which is relayed through the wiring harness to input circuits within the ECUSignals to the ECU include: ignition (onoff), crankshaft position and speed (RPM), throttle position, engine coolant temperature, air temperature, intake manifold air pressure and battery voltageThe ECU compares the input signals to the programmed maps in its memory and determines the appropriate fuel and spark requirements for the immediate operating conditionsThe ECU then sends output signals to set the injector duration and ignition timingSportsman 500 EFI RPM Limit: This EFI system utilizes methods "Hard" LimitIgnition suppression occurs when RPM peaks rapidly: High: 7000 RPM Returns: 6900 RPM "Soft" LimitInjector suppression occurs when RPM reaches peak gradually: High: 7000 RPM Returns: 6900 RPM RPM limits may vary slightly under operating conditions