B2789

MULTIPLEX COMMUNICATION: LIN COMMUNICATION SYSTEM: B2789: No Response from ID BOX
B2789 - No Response from ID BOX

DESCRIPTION

This DTC is output when LIN communication between the certification ECU (smart key ECU) and ID code box (immobilizer code ECU) stops for 10 seconds or more.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
When using the Techstream with the engine switch off to troubleshoot:

Connect the Techstream to the vehicle, and turn a courtesy switch on and off at 1.5 second intervals until communication between the Techstream and vehicle begins.

HINT
DTC B2785 is output when the communication between all of the following components and certification ECU (smart key ECU) stops.

PROCEDURE

1. CLEAR DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

2. CHECK FOR DTC

(a) Recheck for DTC Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B2789 is not output.

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

OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

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

(a) Disconnect the L15 ECU connector.





(b) Disconnect the L32 box connector.

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

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK ID CODE BOX (BATTERY VOLTAGE AND GROUND)

(a) Disconnect the L32 box connector.





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

Standard resistance:





Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. REPLACE ID CODE BOX (IMMOBILIZER CODE ECU)

(a) Temporarily replace the ID code box (immobilizer code ECU) with a new one Removal.

(b) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

6. CHECK FOR DTC

(a) Recheck for DTC Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B2789 is not output.

NG -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Removal

OK -- END (ID CODE BOX IS DEFECTIVE)