B1421

AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Automatic 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 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 B1244.
- If the check is performed in a dark place, DTC B1421/21 or B1424/24 (solar sensor circuit abnormal) may be output even though the system is normal.

PROCEDURE

1. READ VALUE USING TECHSTREAM

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to the ON position and turn Techstream on.

(c) Expose the sensing portion of the solar sensor to light.

HINT
Use an incandescent light for inspection.

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

Data List / Air Conditioner:





OK:

The display is as specified in the normal condition column.

Result:





C -- REPLACE A/C AMPLIFIER

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

2. CHECK HARNESS AND CONNECTOR (SOLAR SENSOR)

(a) Disconnect the solar sensor connector.





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

Standard voltage:





OK -- CHECK SOLAR SENSOR
NG -- Continue to next step.

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

(a) Disconnect the 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 BODY ECU

4. CHECK SOLAR SENSOR

(a) Remove the solar sensor with its connector still connected.





(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:
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 SOLAR SENSOR
OK -- Continue to next step.

5. 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