1A-12 Engine Control System Intake Air Temperature Sensor Intake air temperature sensor is installed to the intake duct. Thermistor is used for the temperature detector as in the thermo sensor to convert the changes of temperature to changes of resistance values and transmits to ECM. Legend 1. Thermistor for ECM 2. Thermistor for thermo meter LNW21ASH001001 Atmospheric Pressure Sensor The atmospheric pressure sensor is incorporated in ECM. MAP (Intake Air Pressure) Sensor The MAP sensor is installed to the cylinder head cover. The MAP sensor is composed of piezo type semiconductor pressure element.
Reference voltage is constantly applied to the MAP sensor from ECM and manifold pressure is detected by the changes of voltage. When the manifold pressure is low (at idling), low voltage signal is sent to ECM and when the pressure is high (at full throttle), high voltage signal is transmitted to ECM. Fuel Temperature Sensor Fuel temperature sensor is installed in the pump chamber full of fuel. Thermistor is used for the temperature detector as in the thermo sensor and convert the changes of temperature to changes of resistance and values transmits to ECM. Vehicle Speed Sensor The vehicle speed sensor is used commonly with the speedometer. ECM receives signal from the speedometer.
By one turn of the speedometer driven gear, 25 pulses are generated indicating 60 km/h at 637rpm. A C B 1 A C B 2 LNW21ASH000801 [Thermistor Characteristics] 30 20 10 ) 7.0 (k 5.0 Value 3.0 2.0 Resistance 1.0 0.7 0.5 0.3 0.2 0.1 -20 0 20 40 60 80 100 120 Engine Coolant Temperature ( C) LNW21ASH000901-X LNW21ASH001101