B2789
NETWORKING: LIN COMMUNICATION SYSTEM: B2789: No Response from ID BOX
DTC B2789 - No Response from ID BOX
DESCRIPTION
This DTC is stored when LIN communication between the certification ECU (smart key ECU assembly) 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 stored when the communication between the ID code box (immobilizer code ECU) and certification ECU (smart key ECU assembly) 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 DTCs Reading and Clearing Diagnostic Trouble Codes.
Result
B -- USE SIMULATION METHOD TO CHECK
A -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ID CODE BOX)
(a) Disconnect the E29 ECU connector.
(b) Disconnect the E28 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 HARNESS AND CONNECTOR (ID CODE BOX - BATTERY AND BODY GROUND)
(a) Disconnect the E28 box connector.
(b) Measure the resistance and voltage according to the value(s) in the tables 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 or normally functioning one Removal.
(b) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
NEXT -- Continue to next step.
6. CHECK FOR DTC
(a) Recheck for DTCs Reading and Clearing Diagnostic Trouble Codes.
Result
B -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
A -- END (ID CODE BOX IS DEFECTIVE)