Mazda TC070-15-01H, Student Manual

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AIR CONDITIONING
SG02 - Control System [Manual Air Conditioning]
SG02-7
TC070-15-01H
Evaporator temperature sensor
A/C signal on/off is controlled by the climate control unit turning the A/C signal
(magnetic clutch) on and off based on the temperature of the air passed through the
evaporator when both the A/C and fan switches are on. This keeps the evaporator
surface temperature within the specified range to prevent the evaporator from being
frosted.
Look at the chart below, Control Reference Value. The predetermined value “t1” must
be above freezing point. The difference between “t1” and “t2” are usually 2 – 3 ºC.
t1 =4.5, t2=5.5 (Mazda 3)
The difference value in temperature between “t1” and “t2” is referred as hysteresis
that prevents continuing repetition of changes ON and OFF at a specified
temperature.
Character of Evaporator Temperature Sensor
Temperature – Resistance Temperature – Voltage (PCM input)