Inspection Procedure

1. PREPARATION: 
2. Remove A/C control assembly with connectors still connected.

1. CHECK: 
   1. Turn ignition switch to ON.
   2. Measure voltage between terminals S5 and TS of A/C control assembly connector when the solar sensor is subjected to an electric light, and when the sensor is covered by a cloth.
      Fig 1: Checking Solar Sensor Circuit Voltage At Terminals S5 & TS

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: 

Fig 2: Determining Solar Sensor Circuit Voltage Based On Light Condition

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

As the inspection light is moved away from the sensor, the voltage increases.

1. NG: Go to step 2. 
2. OK: Proceed to next circuit inspection shown on problem symptoms table see  PROBLEM SYMPTOMS TABLE  . However, if DTC 21 is displayed, check and replace A/C control assembly. 

1. PREPARATION: 
2. Remove solar sensor see AIR CONDITIONING .

1. CHECK: 
   1. Cover the sensor with a cloth.
   2. Measure resistance between terminals 1 and 2 of solar sensor connector.

HINT:

Connect positive (+) lead of ohmmeter to terminal 1 and negative (-) lead to terminal 2 of the solar sensor.

1. OK: 
2. Resistance: Ω.(no continuity) 

1. PREPARATION: 
   1. Remove the cloth from the solar sensor and subject the sensor to electric light.
      Fig 3: Subjecting Solar Sensor To Light Source

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Measure resistance between terminals.

1. OK: 
2. Resistance: Approx. 10 k/ohms (continuity) 

HINT:

As the electric light is moved away from the sensor, the resistance increases.

1. NG: Replace solar sensor. 
2. OK: Go to next step 

1. NG: Repair or replace harness or connector. 
2. OK: Check and replace A/C control assembly.