With Manual Transaxle (MTX)

PURPOSE
The heart of the engine control system is the powertrain control module engine (PCME).
The PCME receives input signals from a series of sensors, makes computations based on these inputs, and sends (output) signals to various devices which control functions such as air/fuel mixture, ignition timing, and certain emission control devices.

OPERATION
The PCME sends out a regulated, 5 volt reference voltage (VREF) to the input sensors. These sensors require a constant VREF source to provide an accurate signal. The PCME monitors the signals from these sensors and calculates the proper operating strategy for the engine operating conditions.


PCME INPUTS
- A/C operation (A/C sensor)
- Air/Fuel ratio (Heated oxygen sensor)
- Barometric absolute pressure (Barometric absolute pressure sensor)
- Braking signal (Stop light switch)
- Cranking signal (ignition switch "START" position)
- E/L operation (Electric load from accessory circuits)
- Engine coolant temperature sensor
- Engine speed (Crankshaft position sensor-SGT signal)
- Manual transaxle in-gear condition (Neutral and clutch switches)
- Intake air amount (Mass air flow sensor)
- Intake air temperature (Intake air temperature sensor)
- No.1 piston @ TDC (Crankshaft position sensor-SGC signal)
- Initial set signal (Data link connector TEN terminal)
- Power steering operation (Steering pressure sensor)
- Throttle valve opening angle (Throttle position sensor)
- Vehicle speed sensor (signal buffer)

PCME OUTPUTS
- A/C cut-off (A/C relay)
- Coolant fan control (coolant fan relay)
- Data link connector (monitor function, output to self diagnosis checker)
- EGR control system (EGR solenoid valves)
- Fail-safe function (Self diagnosis checker and malfunction indicator light)
- Fuel pump control (fuel pump relay)
- Fuel injection system (Fuel injectors)
- Idle speed control (Idle speed control system)
- Ignition timing control (Ignition timing control system-igniter)
- Purge control system (Purge solenoid valve)
- Variable inertia charging (VICS) system (VICS solenoid valves)
- Pressure regulator control (PRC) system (PRC solenoid valves)