DTC B1244: Light Sensor Circuit Malfunction: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Main Body / Data List.
5. Read the display on the Techstream.
   MAIN BODY
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Illumination Rate info	Illumination rate information/0.00 ms to 2162.65 ms	Value is output according to ambient light levels	-

   OK

   Normal condition listed above is displayed.

NG → See step   2 

OK → See step   5 

1. Disconnect the I61*1 or I132*2 automatic light control sensor connector.
2. Disconnect the I13 main body ECU (multiplex network body ECU) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   FOR AUTOMATIC AIR CONDITIONING SYSTEM
   
   

   Tester Connection	Condition	Specified Condition
   I13-22 (CLTE) - I61-3 (CLTE)	Always	Below 1 Ω
   I13-21 (CLTS) - I61-5 (CLTS)	Always	Below 1 Ω
   I13-20 (CLTB) - I61-6 (CLTB)	Always	Below 1 Ω
   I13-22 (CLTE) - Body ground	Always	10 kΩ or higher
   I13-21 (CLTS) - Body ground	Always	10 kΩ or higher
   I13-20 (CLTB) - Body ground	Always	10 kΩ or higher

   FOR MANUAL AIR CONDITIONING SYSTEM
   
   

   Tester Connection	Condition	Specified Condition
   I13-22 (CLTE) - I132-5 (CLTE)	Always	Below 1 Ω
   I13-21 (CLTS) - I132-4 (CLTS)	Always	Below 1 Ω
   I13-20 (CLTB) - I132-3 (CLTB)	Always	Below 1 Ω
   I13-22 (CLTE) - Body ground	Always	10 kΩ or higher
   I13-21 (CLTS) - Body ground	Always	10 kΩ or higher
   I13-20 (CLTB) - Body ground	Always	10 kΩ or higher

   • *1: for Automatic Air Conditioning System
   • *2: for Manual Air Conditioning System

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Reconnect the I13 main body ECU (multiplex network body ECU) connector.
   Fig 1: Inspecting I13 Main Body ECU (Multiplex Network Body ECU) Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage and resistance according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   I13-20 (CLTB) - I13-22 (CLTE)	Ignition switch off	Below 1 V
   	Ignition switch ON	11 to 14 V

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I13-22 (CLTE) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Main Body ECU (Multiplex Network Body ECU))

NG → See step   5 

OK: Go to next step 

1. for Automatic Air Conditioning System
   1. Reconnect the I61 automatic light control sensor connector.
      Fig 2: Inspecting I61 Automatic Light Control Sensor Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Connect an oscilloscope to the automatic light control sensor connector.
      TEXT IN ILLUSTRATION
      
      

      *a	Component with harness connected (Automatic Light Control Sensor)

   3. Check the waveform.

      OK

      Tester Connection	Tool Setting	Condition	Specified Condition
      I61-3 (CLTE) - I61-5 (CLTS)	5 V/DIV., 5 ms./DIV.	Ignition switch ON, light control switch in AUTO position	Correct waveform is as shown in Fig 3

      Fig 3: Identifying Waveform Graph

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      If the ambient light becomes brighter, width A becomes narrower.

2. for Manual Air Conditioning System
   1. Reconnect the I132 automatic light control sensor connector.
      Fig 4: Inspecting I132 Automatic Light Control Sensor Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Connect an oscilloscope to the automatic light control sensor connector.
      TEXT IN ILLUSTRATION
      
      

      *a	Component with harness connected (Automatic Light Control Sensor)

   3. Check the waveform.

      OK

      Tester Connection	Tool Setting	Condition	Specified Condition
      I132-5 (CLTE) - I132-4 (CLTS)	5 V/DIV., 5 ms./DIV.	Ignition switch ON, light control switch in AUTO position	Correct waveform is as shown in Fig 5

      Fig 5: Identifying Waveform Graph

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      If the ambient light becomes brighter, width A becomes narrower.

NG → See step   6 

OK → See step   5