MULTIPLEX COMMUNICATION SYSTEM, Diagnostic DTC:B1249

DTC Code DTC Name
B1249 Double Locking ECU Communication Stop

DESCRIPTION


DTC No. DTC Detection Condition Trouble Area
B1249 Double lock door control relay communication stops
  • Double lock door control relay

  • Wire harness or connector

WIRING DIAGRAM

A0161ZVE04

INSPECTION PROCEDURE

Tech Tips

If "+B of GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1249, repair the "+B or GND short malfunction of communication bus" DTCs first Click here.

PROCEDURE


  1. INSPECT FUSE (MPX-B, DOOR DL)


    1. Remove the MPX-B fuse from the engine room relay block No. 1.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      MPX-B fuse Always Below 1 Ω
      DOOR DL fuse Always Below 1 Ω

    NG
    OK
  2. CHECK HARNESS AND CONNECTOR (DOUBLE LOCK DOOR CONTROL RELAY - BATTERY AND BODY GROUND)


    1. A0160VPE05

      Disconnect the P34 ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      P34-1 (+B) - Body ground Always 11 to 14 V
      P34-7 (CPUB) - Body ground Always 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      P34-14 (GND) - Body ground Always Below 1 Ω

    NG
    OK
  3. CHECK HARNESS AND CONNECTOR (COMMUNICATION LINE)


    1. A01633CE04

      Disconnect the P34 and P33 ECU connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      P34-9 (MPX1) - P33-27 (MPX1) Always Below 1 Ω
      P34-9 (MPX1) - Body ground Always 10 kΩ or higher

    NG
    OK