Air Conditioning System (for Manual Air Conditioning System)

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Manual Air Conditioning System): B1413: Evaporator Temperature Sensor Circuit
B1413 - Evaporator Temperature Sensor Circuit

DESCRIPTION

The No. 1 cooler thermistor is installed on the evaporator in the air conditioning unit to detect the temperature of the cooled air that has passed through the evaporator and control the air conditioning. It sends appropriate signals to the air conditioning amplifier assembly. The resistance of the No. 1 cooler thermistor changes in accordance with the temperature of the cooled air that has passed through the evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies voltage (5 V) to the No. 1 cooler thermistor and reads voltage changes as the resistance of the No. 1 cooler thermistor changes. This sensor is used for frost prevention.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (NO. 1 COOLER THERMISTOR)

(a) Use the Data List to check if the No. 1 cooler thermistor is functioning properly Air Conditioning System (for Manual Air Conditioning System).

Air Conditioner





OK:

The display is as specified in the normal condition column.

Result





B -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal

C -- INSPECT NO. 1 COOLER THERMISTOR

A -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Air Conditioning System (for Manual Air Conditioning System)

2. INSPECT NO. 1 COOLER THERMISTOR

(a) Remove the No. 1 cooler thermistor Removal.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NOTICE:
* Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.
* When measuring, the sensor temperature must be the same as the ambient temperature.

HINT
As the temperature increases, the resistance decreases (refer to the graph).

NG -- REPLACE NO. 1 COOLER THERMISTOR Removal
OK -- Continue to next step.

3. INSPECT AIR CONDITIONING HARNESS ASSEMBLY

(a) Remove the air conditioning harness assembly Disassembly.





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- REPLACE AIR CONDITIONING HARNESS ASSEMBLY Disassembly

OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal