DTC B2287: LIN Communication Master Malfunction; DTC B278C: Lost Communication with Power Source Control [08/2015 - 08/2019]: Procedure

1. Clear the DTCs (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).

Result: 

NEXT 

See step  2

1. Check for DTCs (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).

   OK

   DTC B2287 or B278C is not output.

Result: 

OK 

USE SIMULATION METHOD TO CHECK 

(Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [08/2015 - ] )

Result: 

NG 

See step  3

1. Disconnect the G26 certification ECU connector.
2. Disconnect the G39 power management control ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G26-29 (LIN) - G39-24 (LIN2)	Always	Below 1 Ω
   G26-29 (LIN) or G39-24 (LIN2) - Body ground	Always	10 kΩ or higher

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Disconnect the G39 power management control ECU connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G39-5 (GND2) - Body ground	Always	Below 1 Ω
   G39-6 (GND) - Body ground	Always	Below 1 Ω

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   G39-1 (AM22) - Body ground	Always	11 to 14 V
   G39-2 (AM21) - Body ground	Always	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Rear view of wire harness connector (to Power Management Control ECU)

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

1. Temporarily replace the power management control ECU with a new or normally functioning one (Refer to REMOVAL [08/2015 - 08/2019] ).

Result: 

NEXT 

See step  6

1. Clear the DTCs (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).

Result: 

NEXT 

See step  7

1. Check for DTCs (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).

   OK

   DTC B2287 or B278C is not output.

Result: 

OK 

END (POWER MANAGEMENT CONTROL ECU IS DEFECTIVE) 

Result: 

NG 

REPLACE CERTIFICATION ECU 

(Refer to REMOVAL [08/2015 - 08/2019] )