With Automatic Transaxle (ATX)

PURPOSE
The heart of the engine control system is the engine control module (ECM).
The ECM 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. On automatic transaxle (ATX) equipped vehicles, the ECM also receives inputs from the transaxle control module (TCM).

ECM INPUTS
- A/C operation (A/C sensor)
- Air/Fuel ratio (Heated oxygen sensor)
- Barometric absolute pressure (Barometric pressure sensor)
- Braking signal (Brake switch)
- Cranking signal (ignition switch "START" position)
- E/L operation (Electric load from accessory circuits)
- Engine coolant temperature sensor
- Engine speed (Camshaft position sensor-SGT signal)
- Automatic transaxle in-gear condition (Transaxle range switch)
- Transaxle operating signals (from transaxle control module)
- Intake air amount (Mass air flow sensor)
- Intake air temperature (Intake air temperature sensor)
- No.1 piston @ TDC (Camshaft position sensor-SGC signal)
- Initial set signal (Data link connector TEN terminal)
- Power steering operation (Power steering pressure switch)
- Throttle valve opening angle (Throttle position sensor)
- Vehicle speed sensor

ECM OUTPUTS
- A/C cut-off (A/C relay)
- Fail-safe function (Self diagnosis checker and malfunction indicator lamp)
- Fuel injection system (Fuel injectors)
- Fuel pump control (fuel pump relay)
- Idle speed control (Idle speed control system)
- Ignition timing control (Ignition timing control system-Ignition control module)
- Data link connector (monitor function, output to self diagnosis checker)
- Purge control system (Purge solenoid valve)
- Torque reduced signal/ coolant temperature signal (to transaxle control module, for ATX)
- EGR control system (EGR solenoid valves)
- Variable inertia charging (VICS) system (VICS solenoid valves)
- Pressure regulator control (PRC) system (PRC solenoid valves)