B1200

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: B1200: MPX Body ECU Stop

DTC B1200 - MPX Body ECU Stop

DESCRIPTION

This DTC is detected when communication between the main body ECU and gateway ECU stops for more than 10 seconds.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (DOME)
(a) Remove the DOME fuse from the engine room junction block and 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 (DRIVER SIDE JUNCTION BLOCK - BATTERY AND BODY GROUND)




(a) Disconnect the 1A and 1E junction block 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 COMMUNICATION LINE




(a) Disconnect the 1G junction block connector.
(b) Disconnect the T5, A8 and B5 ECU connectors.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






Result:






C -- REPLACE DRIVER SIDE JUNCTION BLOCK AND REPAIR OR REPLACE HARNESS AND CONNECTOR
B -- REPLACE DRIVER SIDE JUNCTION BLOCK
A -- REPLACE DRIVER SIDE JUNCTION BLOCK