Ignition Switch on (Zero RPM)

PCM READS:

Atmospheric Pressure (MAP sensor)
Engine Temperature (ECT Sensor)
Throttle Position (TPS)

PCM OPERATION:

The PCM calculates basic start-up fuel strategy, using current; atmospheric pressure, engine temperature, and throttle position.

- PCM pre-positions the idle air control motor.

- PCM energizes ASD and fuel pump relays for up to 3 seconds.

- PCM energizes oxygen sensor heating element.

Note: If the key is in the ON or START position and the PCM does not receive an ignition reference signal, (engine is not running), the PCM will deactivate the Automatic Shutdown (ASD) and fuel pump relays within 1 to 3 seconds.