LIN COMMUNICATION SYSTEM, Diagnostic DTC:B1249

DTC Code DTC Name
B1249 Double Locking ECU Communication Stop

DESCRIPTION

DTC B1249 is stored when communication between the double lock door control relay assembly and main body ECU (multiplex network body ECU) stops for more than 10 seconds.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B1249

Double Locking ECU Communication Stop

No communication from the double lock door control relay assembly for more than 10 seconds.

  • Double lock door control relay assembly

  • Main body ECU (multiplex network body ECU)

  • Harness or connector

  • Instrument panel junction block assembly

WIRING DIAGRAM

B339147E05

CAUTION / NOTICE / HINT

Note:

  • When using the GTS with the power switch off to troubleshoot:

    Connect the GTS to the vehicle, and turn a courtesy light switch on and off at 1.5 second intervals until communication between the GTS and vehicle begins.

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

  • When replacing the main body ECU (multiplex network body ECU), make sure to replace it with a new one.

Tip:

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

PROCEDURE

  1. CLEAR DTC

    1. Clear the DTCs.

      Click here

      Body Electrical > Main Body > Clear DTCs

    Result

    Proceed to

    NEXT
    NEXT

  2. CHECK FOR DTC

    1. Check for DTCs.

      Click here

      Body Electrical > Main Body > Trouble Codes

    Result

    Proceed to

    DTC B1249 is output

    DTC B1249 is not output
    DTC B1249 is not output

    USE SIMULATION METHOD TO CHECK

    DTC B1249 is output

  3. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] - DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY)

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

      for LHD:

      Click here

      for RHD:

      Click here

    2. Disconnect the G187 double lock door control relay assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A-16 (LIN2) - G187-9 (MPX1)

      Always

      Below 1 Ω

      A-16 (LIN2) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY)Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY - BATTERY AND BODY GROUND)

    1. B295816C63

      *a

      Front view of wire harness connector

      (to Double Lock Door Control Relay Assembly)

      Disconnect the G187 double lock door control relay assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      G187-7 (GND) - Body ground

      Always

      Below 1 Ω

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      G187-12 (+B) - Body ground

      Power switch off

      11 to 14 V

      G187-11 (CPUB) - Body ground

      Power switch off

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY

    1. Temporarily replace the double lock door control relay assembly with a new or normally functioning one.

      Click here

    2. Clear the DTCs.

      Click here

      Body Electrical > Main Body > Clear DTCs

    Result

    Proceed to

    NEXT
    NEXT

  6. CHECK FOR DTC

    1. Check for DTCs.

      Click here

      Body Electrical > Main Body > Trouble Codes

    Result

    Proceed to

    DTC B1249 is not output

    DTC B1249 is output (for LHD)

    DTC B1249 is output (for RHD)
    DTC B1249 is not output

    END (DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY IS DEFECTIVE)

    DTC B1249 is output (for LHD)

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    Click here

    DTC B1249 is output (for RHD)

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

    Click here

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

    1. Disconnect the 3D instrument panel junction block assembly connector.

    2. Disconnect the G187 double lock door control relay assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      3D-54 - G187-9 (MPX1)

      Always

      Below 1 Ω

      3D-54 - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK (for LHD)

    OK (for RHD)

    NG
    OK (for LHD)

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    Click here

    OK (for RHD)

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR