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
HINT: When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1200, repair the "+B or GND short malfunction of communication bus" DTCs first.

PROCEDURE

1. INSPECT FUSE (ECU-B, INP-J/B, DOOR NO. 1, DOOR NO. 2)
(a) Remove the ECU-B, INP-J/B (*1) and DOOR No. 1 fuses from the fusible link block.
HINT: *1: without Air Suspension System
(b) Remove the DOOR No. 2 fuse from the instrument panel J/B.
(c) 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 main body ECU connector.





(b) Measure the voltage and resistance of the wire harness side connector.
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 B5, 1E, T9 and P22 ECU connectors.
(b) Measure the resistance between the specified terminals on the wire harness side connectors.
Standard resistance:






Result:






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