DTC B14B3-87: Lost Communication with Rear Panel LIN Missing Message [10/2022 - ]: Procedure

Pre-procedure1

• Disconnect the H106 rear seat heater switch connector.

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

  Standard Voltage

  Tester Connection	Condition	Specified Condition	Result
  H106-1 (IG+) - Body ground	Ignition switch ON	10.5 to 16 V	V

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

See step  6

Result: 

OK 

See step  2

Pre-procedure1

• Disconnect the H106 rear seat heater switch connector.

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

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  H106-5 (GND) - Body ground	Always	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

Pre-procedure1

• Disconnect the H106 rear seat heater switch connector.
• Disconnect the C47 air conditioning amplifier assembly connector.

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

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  H106-3 (RLIN) - C47-7 (LIN1)	Always	Below 1 Ω	Ω
  H106-2 (RLIN) or C47-7 (LIN1) - Other terminals and body ground	Always	10 kΩ or higher	kΩ

  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 H106 rear seat heater switch connector.
• Connect the C47 air conditioning amplifier assembly connector.

• Using an oscilloscope, check the waveform.

  Item	Content
  Tester Connection	C47-7 (LIN1) - Body ground
  Tool Setting	2 V/DIV., 20 μs/DIV.
  Condition	Ignition switch ON

  OK

  The waveform displays properly.

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

OK 

See step  5

Pre-procedure1

• Connect the H106 rear seat heater switch connector.

• Using an oscilloscope, check the waveform.

  Item	Content
  Tester Connection	H106-3 (RLIN) - Body ground
  Tool Setting	2 V/DIV., 20 μs/DIV.
  Condition	Ignition switch ON

  OK

  The waveform displays properly.

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

NG 

REPLACE REAR SEAT HEATER SWITCH. Refer to  REMOVAL [10/2022 - ] 

Pre-procedure1

• Disconnect the H106 rear seat heater switch connector.
• Disconnect the C36 engine stop and start ECU connector.

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

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  H106-1 (IG+) - C36-3 (IG41)	Always	Below 1 Ω	Ω
  H106-1 (IG+) or C36-3 (IG41) - Other terminals and body ground	Always	10 kΩ or higher	kΩ

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

OK 

GO TO STOP AND START SYSTEM (Backup Boost Converter Circuit). Refer to  Backup Boost Converter Circuit [10/2022 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR