Engine Control Module: Description and Operation

POWERTRAIN CONTROL MODULE (PCM)

Detects the following:
1. A/C operation from the Air conditioning switch.
2. Air/fuel ratio (Oxygen concentration) from the Heated oxygen sensors.
3. Barometric pressure from the EGR boost sensor.
4. Braking signal from the Brake switch.
5. Cranking signal from the Ignition switch (START position).
6. E/L operation by way of the Cooling fan relay from the Fan switch.
7. Engine coolant temperature from the Engine coolant temperature sensor.
8. Engine speed from the Camshaft position sensor (SGT signal).
9. In-gear condition from the Neutral and clutch switches (MT) or Transmission range switch (AT).
10. Intake air amount from the Mass air flow sensor.
11. Intake air temperature from the Intake air temperature sensor.
12. No.1 piston TDC from the Camshaft position sensor (SGC signal).
13. P/S operation from the Power steering pressure switch.
14. Initial set signal from the Data link connector.
15. Throttle valve opening angle from the Throttle position sensor.
16. OBD II system function from the EGR boost sensor and Crankshaft position sensor (NE signal).

Controls operation of the following:
1. A/C (Cut-off) through the A/C relay.
2. Fail-safe function through the Malfunction Indicator Lamp (MIL).
3. Fuel injection system through the Fuel injector.
4. Idle speed control through the IAC valve.
5. Ignition timing control system through the Ignition control module.
6. On-board diagnostic system through the NGS.
7. Purge control system through the Purge solenoid valve.
8. Lockup control system through the Transmission control module (AT).