Impulse Hatchback L4-1809cc 1.8L DOHC (4XF1-W) (1992)
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Intake Air Temperature Sensor: Description and Operation
MAT Sensor
The Manifold Air Temperature (MAT) Sensor is a thermistor (resistor) whose resistance value varies in relation to the temperature of air entering the
engine. Low temperature results in high resistance (100K ohms at -40°C / -40°F); high temperature results in low resistance (70 ohms at 130°C / 266°F).
The ECM supplies a 5V reference signal to the sensor and by measuring the voltage change can determine the manifold air temperature.
MAT sensor is also used to control spark timing and delays EGR when intake air is cold.
A failure in MAT sensor circuit should set a Code 23.
