B1280

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: B1280: Left Side Junction Block ECU Communication Stop

DTC B1280 - Left Side Junction Block ECU Communication Stop

DESCRIPTION

This DTC is detected when communication between the main body ECU LH (cowl side junction block LH) and network gateway ECU stops for more than 10 seconds.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK FUSE (MPX-B)
(a) Remove the MPX-B from the engine room No. 1 relay block.
(b) Measure the resistance of the fuse.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
2. CHECK WIRE HARNESS (MAIN BODY ECU LH - BATTERY AND BODY GROUND)




(a) Disconnect the PL and PA body ECU connectors.
(b) Measure the resistance and voltage of the wire harness side connectors.
Standard resistance:






Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK RESISTANCE OF COMMUNICATION LINE




(a) Disconnect the V3, A30 and A29 ECU connectors.
(b) Disconnect the LC junction block connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






Result





C -- REPAIR OR REPLACE HARNESS OR CONNECTOR
B -- REPAIR OR REPLACE MAIN BODY ECU LH AND WIRE HARNESS OR CONNECTOR
A -- REPLACE MAIN BODY ECU LH