MX-3 L4-1598cc 1.6L DOHC (1995)
Engine Control Module: Description and Operation
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
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A/C operation (A/C sensor)
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Air/Fuel ratio (Heated oxygen sensor)
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Barometric absolute pressure (Barometric pressure sensor)
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Braking signal (Brake switch)
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Cranking signal (ignition switch "START" position)
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E/L operation (Electric load from accessory circuits)
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Engine coolant temperature sensor
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Engine speed (Camshaft position sensor-SGT signal)
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Automatic transaxle in-gear condition (Transaxle range switch)
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Transaxle operating signals (from transaxle control module)
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Intake air amount (Mass air flow sensor)
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Intake air temperature (Intake air temperature sensor)
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No.1 piston @ TDC (Camshaft position sensor-SGC signal)
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Initial set signal (Data link connector TEN terminal)
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Power steering operation (Power steering pressure switch)
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Throttle valve opening angle (Throttle position sensor)
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Vehicle speed sensor
ECM OUTPUTS
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A/C cut-off (A/C relay)
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Fail-safe function (Self diagnosis checker and malfunction indicator lamp)
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Fuel injection system (Fuel injectors)
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Fuel pump control (fuel pump relay)
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Idle speed control (Idle speed control system)
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Ignition timing control (Ignition timing control system-Ignition control module)
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Data link connector (monitor function, output to self diagnosis checker)
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Purge control system (Purge solenoid valve)
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Torque reduced signal/ coolant temperature signal (to transaxle control module, for ATX)
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EGR control system (EGR solenoid valves)
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Variable inertia charging (VICS) system (VICS solenoid valves)
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Pressure regulator control (PRC) system (PRC solenoid valves)