DTC B2789: No Response from ID BOX: Procedure

WARNING: This page is about a different variant/trim than selected.

CHECK HARNESS AND CONNECTOR (ID CODE BOX - BATTERY AND BODY GROUND)

Disconnect the L10 ID code box connector.

Fig 1: Identifying ID Code Box Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

Tester Connection	Condition	Specified Condition
L10-8 (GND) - Body ground	Always	Below 1 Ω

Standard Voltage

Tester Connection	Condition	Specified Condition
L10-1 (+B) - Body ground	Power switch off	11 to 14 V

TEXT IN ILLUSTRATION

*1	Front view of wire harness connector (to ID Code Box (Immobilizer Code ECU))

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ID CODE BOX)

Disconnect the L62 certification ECU (smart key ECU assembly) connector.

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

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

Standard Resistance

Tester Connection	Condition	Specified Condition
L62-29 (LIN) - L10-3 (LIN1)	Always	Below 1 Ω
L62-29 (LIN) - Body ground	Always	10 kΩ or higher

TEXT IN ILLUSTRATION

*1	Front view of wire harness connector (to Certification ECU (Smart Key ECU Assembly))
*2	Front view of wire harness connector (to ID Code Box (Immobilizer Code ECU))

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

REPLACE ID CODE BOX (IMMOBILIZER CODE ECU)
1. Replace the ID code box (immobilizer code ECU). Refer to REMOVAL .
NEXT: Go to next step
CHECK DTC OUTPUT
1. Clear the DTC. Refer to DTC CHECK / CLEAR .
2. Recheck for DTCs.
  OK
  
  DTC B2789 is not output.
NG → See step 5

OK → END (ID CODE BOX (IMMOBILIZER CODE ECU) WAS DEFECTIVE)
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to REMOVAL