DTC B1244: Light Sensor Circuit Malfunction: Procedure

1. Clear the DTC. Refer to DTC CHECK / CLEAR .
2. Recheck for DTC. Refer to DTC CHECK / CLEAR .

   OK

   DTC B1244 is not output.

NG → See step   2 

OK → See step   7 

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. According to the display on the Techstream, read the Data List.
   MAIN BODY
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Illumination Rate Info	Illumination rate information/ Min.: 0 ms Max.: 2162.65 ms	Actual illumination rate is displayed	-

   OK

   Output illumination is as shown in table above.

NG → See step   3 

OK → See step   5 

1. Disconnect the T1 automatic light control sensor connector.
   Fig 1: Measuring Voltage Of Automatic Light Control Sensor Connector

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   T1-3 (CLTB) - T1-6 (CLTE)	Ignition switch ON	11 to 14 V
   	Ignition switch off	Below 1 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Automatic Light Control Sensor)

3. Reconnect the automatic light control sensor connector.

NG → See step   4 

OK → See step   6 

1. Disconnect the T1 automatic light control sensor connector.
2. Disconnect the D42 main body ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   T1-3 (CLTB) - D42-20 (CLTB)	Always	Below 1 Ω
   T1-4 (CLTS) - D42-21 (CLTS)	Always	Below 1 Ω
   T1-6 (CLTE) - D42-22 (CLTE)	Always	Below 1 Ω
   T1-3 (CLTB) - Body ground	Always	10 kΩ or higher
   T1-4 (CLTS) - Body ground	Always	10 kΩ or higher
   T1-6 (CLTE) - Body ground	Always	10 kΩ or higher

4. Reconnect the main body ECU connector.
5. Reconnect the automatic light control sensor connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   8