Metro L3-61 1.0L (1990)
Engine Control Module: Description and Operation
The ECM is a precision unit consisting of a one chip microcomputer, A/D (Analog/Digital) converter, I/O (Input/Output) unit, ROM (Read Only
Memory) and RAM (Random Access Memory). It is an essential part of the electronic control system, its functions include major functions, as to control
the fuel injector, ISC solenoid valve, fuel pump relay, etc.
The ECM diagnoses troubles which may occur in the system when the ignition switch is "ON" and the engine is running. It indicates the result by turning
on or flashing the "CHECK ENGINE" light when a fault occurs in any of the following systems:
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Oxygen Sensor.
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Coolant Temperature Sensor.
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Throttle Switch (M/T model) or Throttle Position Sensor (A/T model).
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Manifold Air Temperature Sensor.
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Pressure Sensor.
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Ignition Signal.
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Crank Angle Sensor.
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Vehicle Speed Sensor.
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EGR system.
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CPU (Central Processing Unit) of the ECM.
