Automatic Air Conditioning System

AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System): 21: Solar Sensor Circuit

DTC 21 - Solar Sensor Circuit

DESCRIPTION

A photo diode in the A/C solar sensor (cooler (solar sensor) thermistor) detects solar radiation and sends signals to the A/C amplifier.









WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT AIR CONDITIONING AMPLIFIER (TS - S5)





(a) Remove the A/C amplifier with connectors still connected.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
Move the light away from the sensor under the following conditions
Voltage increases
Move the light closer to the sensor under the following conditions
Voltage decreases





HINT: Use an incandescent lamp for inspection. Bring it within 30 cm (11.8 in.) of the A/C solar sensor (cooler (solar sensor) thermistor)

Result:





C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.
2. INSPECT A/C SOLAR SENSOR (COOLER (SOLAR SENSOR) THERMISTOR)





(a) Remove the A/C solar sensor (cooler (solar sensor) thermistor).
(b) Measure the resistance according to the value(s) in the table below.
(c) Connect the positive (+) lead from the ohmmeter to terminal 1 and negative (-) lead to terminal 2 of the A/C solar sensor.
Standard resistance:





NOTE: The connection procedure for using a digital tester such as an TOYOTA electrical tester is shown above. When using an analog tester, connect the positive (+) lead to terminal 2 and negative (-) lead to terminal 1 of the A/C solar sensor.

HINT:
- As the inspection light is moved away from the sensor, the voltage increases.
- Use an incandescent lamp for inspection. Bring it within 30 cm (11.8 in.) of the A/C solar sensor (cooler (solar sensor) thermistor).

NG -- REPLACE A/C SOLAR SENSOR
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (A/C SOLAR SENSOR - AIR CONDITIONING AMPLIFIER)





(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