Inspection Procedure

1. Remove the A/C amplifier with the connectors still connected.
2. Turn the ignition switch ON.
3. Measure the voltage between terminals FRS5 (A48-9) and TS (A48-8) of the A/C amplifier connector when the solar sensor is subjected to an electric light, and when the sensor is covered with a cloth.

   Standard voltage 

   VOLTAGE SPECIFICATION
   
   

   Condition	Specified Condition
   Sensor subjected to electric light	0.8 to 4.3 V
   Sensor covered with a cloth	Below 0.8 V

   HINT:

   • As the inspection light is moved away from the sensor, the voltage increases.
   • However, if DTC 21 is displayed, check and replace the A/C amplifier.

OK: REPLACE AIR CONDITIONING AMPLIFIER 

Fig 1: Measuring Voltage Between Terminals FRS5 (A48-9) And TS (A48-8) Of A/C Amplifier Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to next step 

1. Remove the solar sensor.
2. Connect the positive (+) lead of ohmmeter to terminal 2 and negative (-) lead to terminal 1 of the solar sensor.
3. Measure the resistance between terminals 1 and 2 of the solar sensor connector.

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Condition	Specified Condition
   1 - 2	Sensor subjected to electric light	Excep ∞ Ω
   1 - 2	Sensor is covered with a cloth	∞ Ω

   Fig 2: Checking Solar Sensor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   NOTE: The connection procedure for a digital tester, such as a TOYOTA electrical tester, is shown above. When using an analog tester, connect the negative (-) lead to terminal 1 and positive (+) lead to terminal 2.

   HINT:

   • As the inspect light is moved away from the sensor, the resistance increases.
   • Use an in incandescent light for inspection. Bring it within 30 cm (11.8 in.) of the A/C solar sensor.

NG: REPLACE SOLAR SENSOR 

OK: Go to next step 

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK: REPLACE AIR CONDITIONING AMPLIFIER