B1421

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1421/21: Solar Sensor Circuit (Passenger Side)
B1421/21 - Solar Sensor Circuit (Passenger Side)

DESCRIPTION





The solar sensor, which is installed on the upper side of the instrument panel, detects sunlight and controls air conditioning AUTO mode. The output voltage from the solar sensor varies in accordance with 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 changes in the output voltage from the solar sensor.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Select the item below in the Data List, and read the value displayed on the Techstream.

Data List / Air Conditioner





OK:

The display is as specified in the normal condition column.

Result:





C -- REPLACE A/C AMPLIFIER Removal

B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures
A -- Continue to next step.

2. CHECK SOLAR SENSOR (SENSOR POWER INPUT)

(a) Disconnect the solar sensor connector.





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

Standard Voltage:





NG -- CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SOLAR SENSOR)
OK -- Continue to next step.

3. INSPECT SOLAR SENSOR

(a) Remove the solar sensor.





(b) Reconnect the solar sensor connector.

(c) Turn the engine switch on (IG).

(d) 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 2 and positive (+) lead to terminal 6 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 decreases.

NG -- REPLACE SOLAR SENSOR Removal
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (SOLAR SENSOR - A/C AMPLIFIER)

(a) Disconnect the solar sensor connector.





(b) Disconnect the A/C amplifier connector.





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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE A/C AMPLIFIER Removal

5. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SOLAR SENSOR)

(a) Disconnect the main body ECU connector.





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





Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK RH)