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 prepositions the idle air control motor.
- PCM energizes ASD and fuel pump relays for up to 3 seconds.
- PCM energizes oxygen sensor heating element.
NOTE: When the key is on and the engine is not running, the Automatic Shutdown (ASD) and fuel pump relays are deactivated after 1 to 3 seconds.