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.