DTC B2789: No Response from ID BOX: Procedure

WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

RECONFIRM DTC
1. Clear the DTC and repeat the procedure to re-check it. Refer to DTC CHECK / CLEAR .
  OK
  
  DTC is not output.
OK → END (SYSTEM IS NORMAL)

NG: Go to next step

CHECK WIRE HARNESS (CERTIFICATION ECU - ID CODE BOX)

Disconnect the D39 ECU connector.

Fig 1: Identifying D39 Certification ECU Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the D29 ECU connector.

Fig 2: Identifying D29 ID Code Box Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Resistance

Tester Connection	Condition	Specified Condition
D29-3 (LIN) - D39-10 (LIN)	Always	Below 1 Ω
D29-3 (LIN) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

REPLACE CERTIFICATION ECU (CHECK OPERATION OF CERTIFICATION ECU)
1. Replace the certification ECU.
2. Clear the DTC and repeat the procedure to re-check it. Refer to DTC CHECK / CLEAR .
  OK
  
  DTC is not output.
OK → END (CERTIFICATION ECU IS DEFECTIVE)

NG → REPLACE ID CODE BOX