PCM Components

PCM Components
The PCM is designed to maintain exhaust emission levels to government mandated standards while providing excellent driveability and fuel efficiency. The PCM monitors numerous engine and vehicle functions via electronic sensors such as the throttle position (TP) sensor, heated oxygen sensor (HO2S), and vehicle speed sensor (VSS). The PCM also controls certain engine operations through the following:
- Fuel metering via Fuel injector control
- Ignition Timing via Ignition control module
- Evaporative emission (EVAP) purge
- A/C clutch control
- On-board diagnostics for powertrain functions.
- Automatic Transmission Control System


The PCM is responsible for maintaining proper spark and fuel injection timing for all driving conditions. To provide optimum driveability and emissions, the PCM monitors the input signals from the following components in order to calculate spark timing:
- Engine coolant temperature (ECT) sensor.
- Intake air temperature (IAT) sensor.
- Throttle position (TP) sensor.
- Vehicle speed sensor (VSS).
- Crankshaft position (CKP) sensor.