Starting Mode

With the ignition switch in the RUN position, before engaging the starter, the Engine Control Module (ECM) energizes the fuel pump relay for 2 seconds allowing the fuel pump to build up pressure. The ECM calculates the air/fuel ratio based on inputs from the Mass Air Flow (MAF) sensor. The ECM also uses the Engine Coolant Temperature (ECT), the Throttle Position (TP), and the Manifold Absolute Pressure (MAP) sensors to determine the proper air/fuel ratio for starting. The system stays in starting mode until the engine speed reaches a predetermined RPM.