B1200

MULTIPLEX COMMUNICATION SYSTEM: B1200: MPX Body ECU Stop

DTC B1200 - MPX Body ECU Stop

DESCRIPTION
- This DTC is detected when communication between the instrument panel junction block (multiplex network body ECU) and multiplex network 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. CHECK OPERATION
(a) Check if the wireless door lock control function operates normally through the wireless transmitter.
HINT: With this inspection, the multiplex network body ECU CPU can be diagnosed if it works normally or not.

OK:
Wireless door lock function operates normally.
OK -- CHECK RESISTANCE OF COMMUNICATION LINE
NG -- Continue to next step.
2. INSPECT FUSE (EUC-B NO. 1)
(a) Remove the ECU-B No. 1 fuse from the fusible link block.
(b) Measure the resistance of the fuse.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK BODY ECU - BATTERY AND BODY GROUND)
(a) Disconnect the 1D and 1F instrument panel junction block 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.
4. CHECK RESISTANCE OF COMMUNICATION LINE
(a) Disconnect the 1E fusible link block connector.
(b) Disconnect the B5 and T9 ECU connectors.
(c) Disconnect the P22 switch connector.





(d) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK (MULTIPLEX NETWORK BODY ECU)