Engine Control Module: Description and Operation

Powertrain Control Module (PCM):

The PCM is responsible for maintaining proper spark and fuel injection timing for all driving conditions. Ignition Control (IC) spark timing is the PCM method of controlling spark advance and ignition dwell. To provide optimum driveability and emissions, the PCM monitors input signals from the following components in calculating Ignition Control (IC) spark timing:

^ Ignition Control module (ICM).
^ Engine Coolant Temperature (ECT) sensor.
^ Intake Air Temperature (IAT) sensor.
^ Mass Air Flow (MAF) sensor.
^ Trans Range or PNP inputs from Trans Range switch or Park/Neutral Position switch.
^ Throttle Position (TP) sensor.
^ Vehicle Speed Sensor (VSS) / Trans Output Speed Sensor (TOSS).