5. FUEL INJECTION SYSTEM MXU 500EXi/MXU500i TPS/ISC RESET If close or open the throttle grip randomly, the ECU may record the incorrect TPS when the ECU or the throttle body has been reinstalled. It can cause hard to start engine or idling speed is not smooth when engine installation. ISC has a motor inside, which controls ISC valve to obtain smooth idling speed. The ECU may record the incorrect ISC position during the engine speed isn't working when the ECU or the throttle body has been reinstalled. It can cause engine stop, hard to start engine or rough idling speed. The throttle position sensor (TPS) and idle air bypass valve (ISC) have to be reset when throttle body, T-MAP, TPS, ISC or ECU has been reinstalled. TPS/ISC RESET PROCEDURE Start the engine till engine temperature to 85°C over on idle condition. ECU will automatic learn engine new condition. 5-15