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 instrument panel J/B (driver side J/B ECU) and network gateway ECU stops for more than 10 seconds.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK FUSE (MPX-B, D/C CUT)
(a) Remove the MPX-B from the engine room No. 1 relay block.
(b) Measure the resistance of the fuses.
Standard:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.

2. CHECK WIRE HARNESS (COWL SIDE JUNCTION BLOCK LH - BATTERY AND BODY GROUND)




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






Standard voltage:






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

3. CHECK RESISTANCE OF COMMUNICATION LINE




(a) Disconnect the V3 ECU connector.
(b) Disconnect the LC J/B connector.
(c) Disconnect the b7 switch connector.
(d) Measure the resistance of the wire harness side connectors.
Standard resistance:






Result:






C -- REPAIR OR REPLACE HARNESS AND CONNECTOR
B -- REPLACE COWL SIDE JUNCTION BLOCK LH AND WIRE HARNESS CONNECTOR
A -- REPLACE COWL SIDE JUNCTION BLOCK LH