LIN COMMUNICATION SYSTEM, Diagnostic DTC:B1249

DTC Code DTC Name
B1249 Double Locking ECU Communication Stop

DESCRIPTION

The main body ECU (multiplex network body ECU) stores a DTC when communication with the double lock door control relay assembly is interrupted for 10 seconds or more.

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

  • Double lock door control relay assembly

  • Main body ECU (multiplex network body ECU)

  • Instrument panel junction block assembly

  • Wire harness or connector

WIRING DIAGRAM

A01NHL6E05

INSPECTION PROCEDURE

Tech Tips


  • When using the intelligent tester, repeatedly turn either front door courtesy light switch off-and-on at intervals of 1.5 seconds or less, until communication between the intelligent tester and vehicle begins.

  • When the main body ECU (multiplex network body ECU) has been replaced with a new part, and the cable from negative auxiliary battery terminal (-) is reconnected, the power switch condition will be on (IG). Also, when the auxiliary battery has been removed and installed, the condition will be the same as it was before the auxiliary battery was disconnected.

Note

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

PROCEDURE


  1. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. Remove the instrument panel junction block assembly Click here.

      A01NGJME05

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

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

      Tech Tips

      This inspection is to check the LIN line in the instrument panel junction block assembly that connects the wire harness to the built-in main body ECU (multiplex network body ECU).

      Standard Resistance
      Tester Connection Condition Specified Condition
      2D-27 (LIN2) - MB-16 (LIN2) Always Below 1 Ω
      2D-27 (LIN2) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 *2

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

    NG

    CHECK DTC OUTPUT Click here

    OK

  2. CHECK HARNESS AND CONNECTOR


    1. A01NECDE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Instrument Panel Junction Block Assembly)
      *2

      Front view of wire harness connector

      (to Double Lock Door Control Relay Assembly)

      Disconnect the F84 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
      2D-27 (LIN2) - F84-9 (LIN) Always Below 1 Ω
      2D-27 (LIN2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR


    1. A01NEDCE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Double Lock Door Control Relay Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      F84-1 (+B) - Body ground Always 11 to 14 V
      F84-7 (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
      F84-14 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY


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


    NEXT

  5. CHECK DTC OUTPUT


    1. Clear the DTC Click here.

    2. Recheck for DTCs.

      OK
      DTC B1249 is not output.

    NG

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

    OK

    END (DOUBLE LOCK DOOR CONTROL RELAY WAS DEFECTIVE)