DTC B2287, B278C: LIN Communication Master Malfunction; Lost Communication with Power Source Control: Procedure

1. Clear the DTCs. Refer to DTC CHECK/CLEAR .

NEXT: Go to next step 

1. Check for DTCs. Refer to DTC CHECK/CLEAR .

   OK

   DTC B2287 or B278C is not output.

NG → See step   3 

OK → See step   8 

1. Disconnect the C35 certification ECU (smart key ECU assembly) connector.
2. Disconnect the C43 power source control ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C35-29 (LIN) - C43-24 (LIN2)	Always	Below 1 Ω
   C35-29 (LIN) or C43-24 (LIN2) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the C43 power source control ECU connector.
   Fig 1: Checking Power Source Control ECU - Battery And Body Ground

   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
   C43-5 (GND2) - Body ground	Always	Below 1 Ω
   C43-6 (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
   C43-1 (AM22) - Body ground	Always	11 to 14 V
   C43-2 (AM21) - Body ground	Always	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

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

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Temporarily replace the power source control ECU with a new or normally functioning one. Refer to REMOVAL .

NEXT: Go to next step 

1. Clear the DTCs. Refer to DTC CHECK/CLEAR .

NEXT: Go to next step 

1. Check for DTCs. Refer to DTC CHECK/CLEAR .

   OK

   DTC B2287 or B278C is not output.

NG → See step   9 

OK → END (POWER SOURCE CONTROL ECU IS DEFECTIVE)