Automatic Air Conditioning System

AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System): 11: Room Temperature Sensor Circuit

DTC 11 - Room Temperature Sensor Circuit

DESCRIPTION

This sensor detects the interior temperature that is used as the basis for temperature control and sends appropriate signals to the A/C amplifier.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT A/C ROOM TEMPERATURE SENSOR (COOLER (ROOM TEMP. SENSOR) THERMISTOR))





(a) Remove the A/C room temperature sensor (cooler (room temp. sensor) thermistor).
(b) Measure the resistance according to the value(s) in the table below.





Standard resistance:





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 (see the graph).

NG -- REPLACE A/C ROOM TEMPERATURE SENSOR
OK -- Continue to next step.
2. INSPECT AIR CONDITIONING AMPLIFIER (TR - SG-5)





(a) Remove the A/C amplifier with connector still connected.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:





HINT: As the temperature increases, the voltage decreases.

Result:





C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - A/C ROOM TEMPERATURE SENSOR)





(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE AIR CONDITIONING AMPLIFIER