DTC B2789: No Response from ID BOX [12/2019 - 11/2023]: Procedure

1. Disconnect the H48 certification ECU (smart key ECU assembly) connector.
2. Disconnect the H53 ID code box (immobiliser code ECU) connector.
3. Measure the resistance according to the value(s) in the table below.
   NOTE:

   Make sure that each ECU is in sleep mode before performing the inspection. To enter sleep mode, turn the ignition switch from ON to off and wait for 180 seconds or more without operating any switches.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H48-13 (LIN) - H53-2 (LIN1)	Ignition switch off	Below 1 Ω
   H48-13 (LIN) or H53-2 (LIN1) - Body ground	Ignition switch off	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  2

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   H53-1 (+B) - H53-5 (GND)	Ignition switch off*1 Always*2	11 to 14 V

   1. *1: for HV Model
   2. *2: for Gasoline Model
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H53-5 (GND) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

1. Replace the ID code box (immobiliser code ECU).

   Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  4

1. Register the recognition codes in the ECUs.

   for HV Model: Refer to REGISTRATION [12/2019 - 10/2021] , or refer to REGISTRATION [10/2021 - 11/2023]

   for Gasoline Model: Refer to REGISTRATION [12/2019 - 10/2021] , or refer to REGISTRATION [10/2021 - 10/2022] , or refer to REGISTRATION [10/2022 - 11/2023]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

1. Clear the DTCs.

   Body Electrical > Smart Key > Clear DTCs 

2. Recheck for DTCs.

   Body Electrical > Smart Key > Trouble Codes 

   OK

   DTC B2789 is not output.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

END (ID CODE BOX (IMMOBILISER CODE ECU) WAS DEFECTIVE) 

Result: 

NG 

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [12/2019 - 11/2023]