Kia Optima DL3: Air Conditioning System / Evaporator Temperature Sensor

Kia Optima DL3 2019-2026 Service and Repair Manual / Heating, Ventilation and Air Conditioning / Air Conditioning System / Evaporator Temperature Sensor

Description and operation

Description

The evaporator temperature sensor will detect the evaporator core temperature and interrupt compressor relay power in order to prevent evaporator from freezing by excessive cooling. The evaporator temperature sensor has the Negative Temperature Coefficient (NTC). Electrical resistivity of NTC will increase with decreasing temperature and decrease with increasing temperature.

Repair procedures

Inspection

1.	Turn the ignition switch OFF.

2.	Disconnect the evaporator temperature sensor connector.

Measure the resistance between terminal "+" and "-" of the evaporator temperature sensor.

Specification

Evaporator core temperature [°C (°F)]	Resistance [KΩ]	Voltage [V]
-10 (14)	43.35	2.96
0 (32)	27.62	2.40
10 (50)	18.07	1.88
20 (68)	12.11	1.44
30 (86)	8.30	1.08
40 (104)	5.81	0.81

1. Sensor Ground

2. Evaporator sensor (+)

Replacement

1.	Disconnect the negative (-) battery terminal.

2.	Remove the evaporator core assembly. (Refer to Heater - "Evaporator Core")

3.	Remove the evaporator temperature sensor (A) from the evaporator core.

4.	To install, reverse the removal procedure.

❮A/C Pressure Transducer

Description and operation Description The A/C Pressure Transducer (APT) converts the pressure value of high pressure line into voltage value after measuring it.

In-car Sensor❯

Description and operation Description The In-car air temperature sensor is built in the heater & A/C control unit. The sensor contains a thermistor which measures the temperature of the inside.

Other information:

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Kia Optima DL3 2019-2026 Service and Repair Manual: Heater Core