LIN COMMUNICATION SYSTEM, Diagnostic DTC:B1249

DTC Code DTC Name
B1249 Double Locking ECU Communication Stop

DESCRIPTION

This DTC is stored when LIN communication between the double lock door control relay assembly and main body ECU (multiplex network body ECU) stops for 10 seconds or more.

DTC No. DTC Detection Condition Trouble Area
B1249 No communication between the double lock door control relay assembly and main body ECU (multiplex network body ECU) for 10 seconds or more.

  • Double lock door control relay assembly

  • Main body ECU (multiplex network body ECU)

  • Harness or connector

WIRING DIAGRAM

A005LW8E04

CAUTION / NOTICE / HINT

Note


  • When using the intelligent tester with the ignition switch off to troubleshoot:

    Connect the intelligent tester to the vehicle, and turn the courtesy switch on and off at 1.5-second intervals until communication between the tester and vehicle begins.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips

When communication between the double lock door control relay assembly and main body ECU (multiplex network body ECU) stops, DTC B2325 is also stored.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTC Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTC Click here.

      Result
      Result Proceed to
      DTC B1249 is output A
      DTC B1249 and B2325 are output B

      Tech Tips

      When both B1249 and B2325 are output at the same time, troubleshoot B2325 first.


    B

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

    A

  3. CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    A005L10E01
    Text in Illustration
    *a

    Component without harness connected

    (Instrument Panel Junction Block Assembly)

    1. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly Click here.

    2. Disconnect the 3B instrument panel junction block assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      MB-16 (LIN2) - 3B-26 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      MB-16 (LIN2) or 3B-26 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

  4. CHECK HARNESS AND CONNECTOR INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY)


    1. Disconnect the F79 double lock door control relay assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      3B-26 - F79-9 (MPX1) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      3B-26 or F79-9 (MPX1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  5. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

    A005KKBE01
    Text in Illustration
    *a

    Front view of wire harness connector

    (to Double Lock Door Control Relay Assembly)

    1. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      F79-1 (+B) - Body ground Always 11 to 14 V
      F79-7 (CPUB) - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F79-14 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  6. REPLACE DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY


    1. Replace the double lock door control relay assembly Click here.


    NEXT

  7. CHECK FOR DTC


    1. Clear the DTC Click here.

    2. Recheck for DTC.

      Result
      Result Proceed to
      DTC B1249 is not output A
      DTC B1249 is output B

    A

    END (DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here