Ignition Switch

Ignition switch sends signal to PCM indicating whether switch is on, off or cranking (ST). When PCM receives ON signal, it energizes ASD relay coil and supplies power to sensors and actuators. When PCM receives ST signal, it controls fuel injection rate, idle speed, ignition timing, etc. for optimum cranking conditions. Intake Air Temperature Sensor

Sensor measures temperature of incoming intake air. This information is used by PCM to adjust air/fuel mixture.