LIN Communication System

NETWORKING: LIN COMMUNICATION SYSTEM: B2789: No Response from ID BOX

DTC B2789 - No Response from ID BOX

DESCRIPTION

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






WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
- If the certification ECU (smart key ECU assembly) is replaced, register the keys and ECU communication ID Engine Immobiliser System (W/ Smart Key System).
- If the ID code box (immobiliser code ECU) is replaced, register the ECU code and ECU communication ID Engine Immobiliser System (W/ Smart Key System).

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 the DTC Reading and Clearing Diagnostic Trouble Codes.
OK:
B2789 is not output.
NG -- CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ID CODE BOX)
OK -- USE SIMULATION METHOD TO CHECK
3. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ID CODE BOX)




(a) Disconnect the E36 and E22 connectors.
(b) 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 HARNESS AND CONNECTOR (ID CODE BOX BATTERY VOLTAGE AND GROUND)




(a) 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 (IMMOBILISER CODE ECU)
(a) Replace the ID code box (immobiliser code ECU) Removal.
NEXT -- Continue to next step.
6. CHECK FOR DTC
(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(b) Recheck for the DTC.
OK:
B2789 is not output.
NG -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
OK -- END (ID CODE BOX (IMMOBILISER CODE ECU) IS DEFECTIVE)