Powertrain Control Module (PCM)

The PCM controls all ignition system functions, and constantly corrects the basic spark timing. The PCM monitors information from various sensor inputs that include the following:
^ The Throttle Position (TP) sensor
^ The Engine Coolant Temperature (ECT) Sensor
^ The Mass Airflow (MAF) Sensor
^ The Intake Air Temperature (IAT) sensor
^ The Vehicle Speed Sensor (VSS)
^ The transmission gear position or range information sensors
^ The Engine Knock Sensor (KS)