DTC B1244: Light Sensor Circuit [11/2020 - 12/2023]: Procedure

Pre-procedure1

• Clear the DTCs.

  Body Electrical > Main Body > Clear DTCs 

• Turn the ignition switch ON and wait for at least 5 seconds or more.

• Check for DTCs.

  Body Electrical > Main Body > Trouble Codes 

  Result

  Result	Proceed to
  B1244 is not output	A
  B1244 is output	B

Post-procedure1

• None

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2020 - ] 

Result: 

B 

See step  2

1. According to the display on the GTS, read the Data List and check that the value of Light Sensor Illuminance changes while performing the following:
   1. Cover the automatic light control sensor with an opaque object.
   2. Slowly move the opaque object to uncover and then cover the automatic light control sensor.

      Body Electrical > Main Body > Data List 

      Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
      Light Sensor Illuminance	Light control sensor illuminance	0 to 8191 lx or SensorFail	Value is output according to ambient light level	-

      Body Electrical > Main Body > Data List 

      Tester Display
      Light Sensor Illuminance

      OK

      The value changes according to the amount the automatic light control sensor is covered.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022]  , or refer to  REMOVAL [12/2022 - 12/2023] 

Result: 

NG 

See step  3

Pre-procedure1

• Disconnect the D13 automatic light control sensor connector.
• Disconnect the D11 main body ECU (multiplex network body ECU) connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition
  D13-1 (CLTB) - D11-23 (CLTB)	Always	Below 1 Ω
  D13-4 (CLTS) - D11-24 (CLTS)	Always	Below 1 Ω
  D13-2 (CLTE) - D11-25 (CLTE)	Always	Below 1 Ω
  D13-1 (CLTB) or D11-23 (CLTB) - Body ground	Always	10 kΩ or higher
  D13-4 (CLTS) or D11-24 (CLTS) - Body ground	Always	10 kΩ or higher
  D13-2 (CLTE) or D11-25 (CLTE) - Body ground	Always	10 kΩ or higher

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

Pre-procedure1

• Disconnect the D13 automatic light control sensor connector.

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

• Measure the voltage according to the value(s) in the table below.

  Standard Voltage

  Tester Connection	Switch Condition	Specified Condition
  D11-23 (CLTB) - D11-25 (CLTE)	Ignition switch ON	11 to 14 V

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022]  , or refer to  REMOVAL [12/2022 - 12/2023] 

Result: 

OK 

See step  5

1. Inspect the automatic light control sensor.

   Refer to ON-VEHICLE INSPECTION [11/2020 - ]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [11/2020 - 11/2021]  , or refer to  REMOVAL [11/2021 - 12/2022]  , or refer to  REMOVAL [12/2022 - 12/2023] 

Result: 

NG 

REPLACE AUTOMATIC LIGHT CONTROL SENSOR. Refer to  REMOVAL [11/2020 - ]