Starting Mode

When the ignition is first turned ON, the ECM supplies ignition voltage to the fuel pump flow control module when the ECM detects that the ignition is ON. The voltage signal from the ECM to the fuel pump flow control module remains active for two seconds, unless the engine is in Crank or Run. This allows the fuel pump to build pressure in the fuel system. The control module calculates the air/fuel ratio based on inputs from the engine coolant temperature (ECT), manifold absolute pressure (MAP), mass air flow (MAF), and throttle position (TP) sensors. The system stays in starting mode until the engine speed reaches a predetermined RPM.