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 and main body ECU (instrument panel junction block assembly) stops for more than 10 seconds.

DTC Code

DTC Detection Condition

Trouble Area

B1249

Communication between the double lock door control relay and main body ECU (instrument panel junction block assembly) stops for more than 10 seconds.

  • Double lock door control relay assembly

  • Main body ECU (instrument panel junction block assembly)

  • Harness or connector

WIRING DIAGRAM

E180188E04

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 a courtesy light switch on and off at 1.5 second intervals until communication between the intelligent tester and vehicle begins.

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

Tip:

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

PROCEDURE

  1. CLEAR DTC

    1. Clear the DTCs (Click here).

  2. CHECK FOR DTC

    1. Check for DTCs (Click here).

      Table 1. Result:

      Result

      Proceed to

      DTC B1249 is output

      A

      DTC B1249 is not output

      B

    USE SIMULATION METHOD TO CHECK

    (Click here)

  3. CHECK HARNESS AND CONNECTOR (DOUBLE LOCK DOOR CONTROL RELAY - MAIN BODY ECU)

    U123787E02

    1. Disconnect the H79 ECU connector.

    2. Disconnect the H50 relay connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H50-9 (MPX1) - H79-23 (LIN2)

      Always

      Below 1 Ω

      H50-9 (MPX1) - Body ground

      Always

      10 kΩ or higher
      Table 2. Text in Illustration

      *1

      Front view of wire harness connector

      (to Main Body ECU)

      *2

      Front view of wire harness connector

      (to Double Lock Door Control Relay)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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

    U123788E02

    1. Disconnect the H50 relay connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H50-14 (GND) - Body ground

      Always

      Below 1 Ω

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      H50-1 (+B) - Body ground

      Always

      11 to 14 V

      H50-7 (CPUB) - Body ground

      Always

      11 to 14 V
      Table 3. Text in Illustration

      *1

      Front view of wire harness connector

      (to Double Lock Door Control Relay)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. REPLACE DOUBLE LOCK DOOR CONTROL RELAY ASSEMBLY

    1. Temporarily replace the double lock door control relay with a new or normally functioning one (Click here).

    2. Clear the DTCs (Click here).

  6. CHECK FOR DTC

    1. Check for DTCs (Click here).

      Table 4. Result

      Result

      Proceed to

      DTC B1249 is not output

      A

      DTC B1249 is output

      B

    END (DOUBLE LOCK DOOR CONTROL RELAY IS DEFECTIVE)

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)