B1268

LIGHTING: LIGHTING SYSTEM: B1268: Back-up Communication Bus Malfunction

DTC B1268 - Back-up Communication Bus Malfunction

DESCRIPTION

This DTC is output when a B+ or GND short occurs on the back-up communication bus (BU+, BU-).






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT LUGGAGE ROOM JUNCTION BLOCK
(a) Disconnect the L24 ECU connector.
(b) Check the DTC.
OK:
DTC B1268 is not output.
OK -- REPLACE LUGGAGE ROOM JUNCTION BLOCK
NG -- Continue to next step.
2. INSPECT TURN SIGNAL SWITCH ASSEMBLY
(a) Connect the L24 ECU connector.
(b) Disconnect the C11 switch connector.
(c) Check the DTC.
OK:
DTC B1268 is not output.
OK -- REPLACE TURN SIGNAL SWITCH ASSEMBLY
NG -- Continue to next step.
3. CHECK WIRE HARNESS (DRIVER SIDE JUNCTION BLOCK ECU - SWITCH)




(a) Disconnect the D4 ECU connector.
(b) Disconnect the C11 switch connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
4. CHECK WIRE HARNESS (DRIVER SIDE JUNCTION BLOCK ECU - LUGGAGE ROOM JUNCTION BLOCK ECU)




(a) Disconnect the D3 ECU connector.
(b) Disconnect the L24 ECU connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- REPLACE DRIVER SIDE JUNCTION BLOCK