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 RH and network gateway ECU stops for more than 10 seconds.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (MPX-B, D/C CUT)
(a) Remove the MPX-B and D/C CUT fuses from the engine room No. 1 relay block.
(b) Measure the resistance of the fuses.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
2. CHECK WIRE HARNESS (MAIN BODY ECU RH - BATTERY AND BODY GROUND)




(a) Disconnect the DA and DK ECU connectors.
(b) Measure the resistance and voltage of the wire harness side connectors.
Standard voltage:





Standard resistance





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




(a) Disconnect the DA, K66, K68 and K27 ECU connectors.
(b) Disconnect the K22 switch 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 RH AND REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR
A -- REPLACE MAIN BODY ECU RH