DTC B2789: ID Code Box Communication [11/2021 - ]: Procedure

1. Turn the ignition switch to ON.
2. Using the GTS, perform the clear DTCs of [Keyless Access with Push Button Start(Collation)].
3. Read the DTC of [Keyless Access with Push Button Start(Collation)] using the GTS.

   Is DTC B2789 displayed? (Current code)

   Result	Proceed to
   Yes	A
   No (Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.)	B

Result: 

B 

END 

1. Even if DTC is displayed, the circuit has returned to a normal condition at this time.
2. Reproduce the failure, and then perform the diagnosis again.

   HINT: 

   In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.

Result: 

A 

See step  2

1. Turn the ignition switch to OFF.
2. Disconnect the smart key ECU assembly connector.
3. Using a tester, measure the resistance between the smart key ECU assembly connector and chassis ground.

   Connector & terminal

   F9-20 (LIN1) - Chassis ground

   Is the resistance 10 kΩ or more?

   Result	Proceed to
   Yes	A
   No (Repair or replace the short circuit of the harness.)	B

Result: 

B 

REPAIR OR REPLACE THE SHORT CIRCUIT OF THE HARNESS 

Result: 

A 

See step  3

1. Disconnect the immobilizer code ECU connector.
2. Using a tester, measure the resistance between the smart key ECU assembly connector and the immobilizer code ECU connector.

   Connector & terminal

   F9-20 (LIN1) - A74-2

   Is the resistance less than 1 Ω?

   Result	Proceed to
   Yes	A
   No (Repair or replace the open circuit of harness.)	B

Result: 

B 

REPAIR OR REPLACE THE OPEN CIRCUIT OF HARNESS 

Result: 

A 

See step  4

1. Using a tester, measure the resistance between immobilizer code ECU connector and chassis ground.

   Connector & terminal

   A74-5 - Chassis ground

   Is the resistance less than 1 Ω?

   Result	Proceed to
   Yes	A
   No (Repair or replace the open circuit of harness.)	B

Result: 

B 

REPAIR OR REPLACE THE OPEN CIRCUIT OF HARNESS 

Result: 

A 

See step  5

1. Using a tester, measure the voltage between immobilizer code ECU connector and chassis ground.

   Connector & terminal

   A74-1 (+) - Chassis ground (-)

   Is the voltage 11 - 14 V?

   Result	Proceed to
   Yes	A
   No (Repair or replace the faulty portion of the power supply circuit.)	B

Result: 

B 

REPAIR OR REPLACE THE FAULTY PORTION OF THE POWER SUPPLY CIRCUIT 

Result: 

A 

See step  6

1. Turn the ignition switch to ON.
2. Using the GTS, perform the clear DTCs of [Keyless Access with Push Button Start(Collation)].
3. Read the DTC of [Keyless Access with Push Button Start(Collation)] using the GTS.

   Is DTC B2789 displayed? (Current code)

   Result	Proceed to
   Yes (Replace the immobilizer code ECU.)	A
   No	B

Result: 

A 

REPLACE IMMOBILIZER CODE ECU. Refer to  REMOVAL [11/2021 - ] 

Result: 

B 

See step  7

1. Using the GTS, perform the clear DTCs of [Keyless Access with Push Button Start(Collation)].
2. Read the DTC of [Keyless Access with Push Button Start(Collation)] using the GTS.

   Is DTC B2785 displayed? (Current code)

   Result	Proceed to
   Yes (Replace the smart key ECU assembly.)	A
   No (Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.) HINT:  In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.	B

Result: 

A 

REPLACE SMART KEY ECU ASSEMBLY. Refer to  REMOVAL [11/2021 - ] 

Result: 

B 

END 

1. Even if DTC is displayed, the circuit has returned to a normal condition at this time.
2. Reproduce the failure, and then perform the diagnosis again.

   HINT: 

   In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.