Inspection Procedure

HINT:

In case of using the LEXUS hand-held tester, start the inspection step 1 and in case of not using the LEXUS hand-held tester, start from step  2.

1. Check solar sensor using LEXUS hand-held tester. 

   PREPARATION: 

   Connect the LEXUS hand-held tester to the DLC3.

   CHECK: 

   Check the solar sensor using DATA LIST.

   1. OK : Check and replace A/C ECU. 
   2. NG : Go to next step. 
2. Check voltage between terminals TSRr and S5-4 of A/C ECU connector. 

   PREPARATION: 

   Remove A/C ECU with connectors still connected.

   CHECK: 

   1. Turn ignition switch to ON.
   2. Measure voltage between terminals TSRr and S5-4 of A/C ECU connector when the solar sensor is subjected to an electric light, and when the sensor is covered by al cloth.
   Fig 1: Identifying Terminals TSRR And S5-4 Of A/C ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: 

   VOLTAGE CONDITION SPECIFICATION
   
   

   Condition	Voltage
   Sensor subjected to electric light	0.8 - 4.3 V
   Sensor covered by a cloth	Below 0.8 V

   HINT:

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

   1. NG : Go to step 3. 
   2. OK : Proceed to next circuit inspection shown on problem symptoms table (See  PROBLEM SYMPTOMS TABLE  ). However, if DTC B1428/28 is displayed, check and replace A/C ECU. 
3. Check solar sensor. 

   PREPARATION: 

   Remove solar sensor.

   CHECK: 

   1. Cover the sensor with a cloth.
   2. Measure voltage 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.

   OK: 

   Voltage: Below 1.0 V 

   Fig 2: Identifying Solar Sensor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   PREPARATION: 

   1. Remove the cloth from the solar sensor and subject the sensor to electric light.
   2. Measure voltage.

   OK: 

   Voltage: Approx. 0.4 V 

   HINT:

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

   1. NG : Replace solar sensor. 
   2. OK : Go to next step. 
4. Check harness and connector between A/C ECU and solar sensor (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
   1. NG : Repair or replace harness or connector. 
   2. OK : Check and replace A/C ECU.