DTC B2405: Sub Bus LIN Module Communication Malfunction: Procedure

1. Disconnect the L33 ECU connector.
   Fig 1: Identifying L33 ECU And R12 Junction Block Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the R12 junction block connector.
3. Measure the resistance and voltage according to the value(s) in the tables below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   L33-10 (MPX) - R12-2 (LIN)	Always	Below 1 Ω
   L33-10 (MPX) - Body ground	Always	10 kΩ or higher

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   L33-10 (MPX) - Body ground	Always	Below 1 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the R7 junction block connector.
   Fig 2: Identifying R7 Junction Block Connector Terminals

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   R7-16 (GND9) - Body ground	Always	Below 1 Ω

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   R7-6 (+B2) - Body ground	Always	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Temporarily replace the overhead junction block with a new or normally functioning one. Refer to DISASSEMBLY .
2. Clear the DTC. Refer to DTC CHECK / CLEAR .

NEXT: Go to next step 

1. Recheck for DTCs. Refer to DTC CHECK / CLEAR .
   RESULT
   
   

   Result	Proceed to
   DTC B2405 is not output	A
   DTC B2405 is output	B

B → See step   5 

A → END (OVERHEAD JUNCTION BLOCK IS DEFECTIVE)