MULTIPLEX COMMUNICATION SYSTEM, Diagnostic DTC:B1200

DTC Code DTC Name
B1200 MPX Body ECU Stop

DESCRIPTION


DTC No. DTC Detection Condition Trouble Area
B1200 Main body ECU RH (cowl side junction block RH) communication stops

  • Main body ECU RH (cowl side junction block RH)

  • Wire harness or connector

WIRING DIAGRAM

A0160DPE08

INSPECTION PROCEDURE

Tech Tips

If "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1200, perform troubleshooting for the "+B or GND short malfunction of communication bus" DTCs first Click here.

PROCEDURE


  1. INSPECT FUSE (FR DOOR RH)


    1. Remove the FR DOOR RH fuse from the main body ECU RH (cowl side junction block RH).

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      FR DOOR RH fuse Always Below 1 Ω

    NG

    REPLACE FUSE (FR DOOR RH)

    OK

  2. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - BATTERY AND BODY GROUND)


    1. Disconnect the RN and RD connectors.

      A015YLHE04

    2. Measure the voltage and resistance according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      RN-1 (BATB) - Body ground Always 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      RD-7 (GND2) - Body ground Always Below 1 Ω
      RD-17 (GND1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (COMMUNICATION LINE)


    1. Disconnect the J75, J76, P33 and RJ ECU connectors*1.

    2. Disconnect the L22, RJ, J75 and J76 ECU connectors*2.

      A01620RE05

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      J75-21 (MPX2) - J76-3 (MPD1) Always Below 1 Ω

      RJ-21 (MPX1) - P33-27 (MPX1)*1

      RJ-21 (MPX1) - L22-2 (MPX2)*2

      		 Always Below 1 Ω

      • *1: for LHD

      • *2: for RHD


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE MAIN BODY ECU RH (COWL SIDE JUNCTION BLOCK RH)