Starting Mode

When the ignition is first turned ON before engaging the starter, the PCM energizes the fuel pump relay for a calibrated time, approximately 2 seconds, allowing the fuel pump to build up pressure. The PCM also checks the Engine Coolant Temperature (ECT) and Throttle Position (TP) sensors to determine the proper air/fuel ratio for starting. The air/fuel ratio ranges from approximately 0.8:1 at -40° C (-40° F) to 16.8:1 at 110° C (230° F) engine coolant temperature. The PCM controls the amount of fuel delivered by changing how long the injectors are energized. This is done by pulsing the injectors for very short times.