Starting Mode

With the ignition switch in RUN position, before engaging the starter, the PCM energizes the fuel pump relay for 2 seconds allowing the fuel pump to build up pressure. The PCM first tests speed density, then switches to the Mass Airflow (MAF) sensor. The PCM 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 PCM controls the amount of fuel delivered in the starting mode by changing the pulse width of the injectors. The PCM controls the amount of fuel delivered in the starting mode by changing the width of the fuel injectors pulse.