Ignition Switch on (Zero RPM)

This is an OPEN LOOP mode.

When the SFI system is ACTIVATED by the ignition switch, the following actions occur:

- The PCM preposition the idle air control (IAC) motor.

- The PCM reads atmospheric air pressure from the manifold absolute pressure (MAP) sensor and calculates the basic fuel strategy.

- The PCM monitors the throttle position sensor (TPS) and engine coolant temperature (ECT) sensor input. The PCM uses these inputs to modify fuel strategy.

- Oxygen sensor heating element is energized.

- On flexible fuel (FFV) vehicles, for 2 seconds, the methanol concentration sensor calibrates the PCM. During the calibration period the sensor sends 4.45 volts to the PCM as a correction factor. After the calibration period, the sensor output represents the methanol percentage in the fuel.

When the key is turned to the ON position, neither the Auto Shutdown (ASD) relay or the fuel pump relay are ACTIVATED. For this reason, battery voltage is not supplied to the ignition coil, fuel pump, injectors, oxygen sensor heater, or alternator field.