Air Conditioning System

AIR CONDITIONING: AIR CONDITIONING SYSTEM: 24: Solar Sensor Circuit (Driver Side)

DTC 24 - Solar Sensor Circuit (Driver Side)

DESCRIPTION





The solar sensor, which is installed on the upper side of the instrument panel, detects sunlight and controls the air conditioning in AUTO mode. The output voltage from the solar sensor varies according to the amount of sunlight. When the sunlight increases, the output voltage increases. As the sunlight decreases, the output voltage decreases. The A/C amplifier detects voltage output from the solar sensor.






WIRING DIAGRAM





INSPECTION PROCEDURE
HINT:
- If DTC B1244 is output at the same time, troubleshoot DTC B1244 first [1][2]B Code Charts.
- If the check is performed in a dark place, DTC 21 or 24 (solar sensor circuit abnormal) may be output even though the system is normal.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (SOLAR SENSOR)




(a) Disconnect the connector from the solar sensor.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






OK -- INSPECT COOLER (SOLAR SENSOR) THERMISTOR
NG -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (BODY ECU - SOLAR SENSOR)
(a) Check for open and short circuit in the harness and the connector between the body ECU and the solar sensor Electronic Circuit Inspection Procedure.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE BODY ECU
3. INSPECT COOLER (SOLAR SENSOR) THERMISTOR




(a) Remove the solar sensor.
(b) Connect the positive (+) lead from the battery to terminal 6 (CLTB), and the negative (-) lead to terminal 3 (CLTE) of the solar sensor.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:





NOTICE:
- The connection procedure for using a digital tester such as a TOYOTA electrical tester is shown above. When using an analog tester, connect the negative (-) lead to terminal 6, and the positive (+) lead to terminal 3 of the solar sensor.
- While using the battery during inspection, do not bring the positive and negative tester probes too close to each other as a short circuit may occur.
HINT:
- Use an incandescent light for inspection. Bring it within about 30 cm (11.8 in.) of the solar sensor.
- As the inspection light is moved away from the sensor, the voltage increases.

NG -- REPLACE COOLER (SOLAR SENSOR) THERMISTOR
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (COOLER (SOLAR SENSOR) - AIR CONDITIONING AMPLIFIER)
(a) Check for open and short circuit in the harness and the connector between the solar sensor and the A/C amplifier Electronic Circuit Inspection Procedure.
Result:






C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- REPAIR OR REPLACE HARNESS OR CONNECTOR