B1413

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1413: Evaporator Temperature Sensor Circuit
B1413 - Evaporator Temperature Sensor Circuit

DESCRIPTION

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

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





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (EVAPORATOR FIN THERMISTOR)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Data List.

(e) According to the display on the Techstream, read the Data List.

Air Conditioner





OK:

The display is as specified in the normal condition column.

Result





B -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures

C -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal
A -- Continue to next step.

2. INSPECT FRONT EVAPORATOR TEMPERATURE SENSOR (NO. 1 COOLER THERMISTOR)

(a) Inspect the front evaporator temperature sensor (No. 1 cooler thermistor) Testing and Inspection.

NG -- REPLACE FRONT EVAPORATOR TEMPERATURE SENSOR (NO. 1 COOLER THERMISTOR) Removal
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - FRONT EVAPORATOR TEMPERATURE SENSOR)

(a) Disconnect the D16 air conditioning amplifier assembly connector.

(b) Disconnect the D10 front evaporator temperature sensor (No. 1 cooler thermistor) connector.

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

Standard Resistance:





(d) Reconnect the front evaporator temperature sensor (No. 1 cooler thermistor) connector.

(e) Reconnect the air conditioning amplifier assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal