DESCRIPTION
The evaporator temperature sensor (A/C thermistor) is installed on the evaporator in the air conditioning unit to detect the cooled air temperature that has passed through the evaporator and to control the air conditioning. It sends appropriate signals to the A/C amplifier. The resistance of the evaporator temperature sensor (A/C thermistor) changes in accordance with the cooled air temperature that has passed through the evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The A/C amplifier applies voltage (5 V) to the evaporator temperature sensor (A/C thermistor) and reads voltage changes as the resistance of the evaporator temperature sensor (A/C thermistor) changes. This sensor is used for frost prevention.
DTC No. | DTC Detection Condition | Trouble Area |
---|---|---|
B1413/13 | Open or short in evaporator temperature sensor circuit |
|
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
READ VALUE USING INTELLIGENT TESTER
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Turn the intelligent tester on.
Enter the following menus: Body / Air Conditioner / Data List.
Check the value(s) by referring to the table below.
Tester Display | Measurement Item/Range | Normal Condition | Diagnostic Note |
---|---|---|---|
Evaporator Fin Thermistor | Evaporator temperature sensor / Min.: -29.7°C (-21.46°F) Max.: 59.55°C (139.19°F) |
Actual evaporator temperature displayed | - |
OK |
---|
The display is as specified in the Normal Condition column. |
Result | ||||||||
---|---|---|---|---|---|---|---|---|
|
B |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here |
C |
REPLACE A/C AMPLIFIER Click here |
A |
INSPECT EVAPORATOR TEMPERATURE SENSOR
Remove the evaporator temperature sensor.
Disconnect the evaporator temperature sensor connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Note
Hold the sensor only by its connector. Touching the sensor may change the resistance value.
When measuring, the sensor temperature must be the same as the ambient temperature.
Tech Tips
As the temperature increases, the resistance decreases (see the graph).
NG |
REPLACE EVAPORATOR TEMPERATURE SENSOR Click here |
OK |
INSPECT AIR CONDITIONING HARNESS (A/C AMPLIFIER - EVAPORATOR TEMPERATURE SENSOR)
Remove the air conditioning harness.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
NG |
REPLACE AIR CONDITIONING HARNESS Click here |
OK |
REPLACE A/C AMPLIFIER Click here