LIN COMMUNICATION SYSTEM, Diagnostic DTC:B1273

DTC Code DTC Name
B1273 Sliding Roof ECU Communication Stop

DESCRIPTION

This DTC is stored when LIN communication between the sliding roof ECU and main body ECU (cowl side junction block LH) stops for 10 seconds or more.

DTC Code DTC Detection Condition Trouble Area
B1273 No communication between the sliding roof ECU and main body ECU (cowl side junction block LH) for 10 seconds or more.

  • Sliding roof ECU

  • Main body ECU (cowl side junction block LH)

  • Harness or connector

WIRING DIAGRAM

A01X192E85

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

Tech Tips

DTC B2325 is stored when the communication between the sliding roof ECU and main body ECU (cowl side junction block LH) stops.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTC Click here.


    NEXT

  2. CHECK FOR DTC


    1. Recheck for DTCs Click here.

      Result
      Result Proceed to
      DTC B1273 is output A
      DTC B1273 is not output B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  3. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SLIDING ROOF ECU)

    A01XAGGE02
    *1 Front view of wire harness connector:
    *2 (to Main Body ECU)
    *3 (to Sliding Roof ECU)

    1. Disconnect the E3 and R5 ECU connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E3-10 (LIN2) - R5-4 (MPX1) Always Below 1 Ω
      E3-10 (LIN2) or R5-4 (MPX1) - Body ground Always 10 kΩ or higher
      Standard Voltage
      Tester Connection Condition Specified Condition
      R5-4 (MPX1) - Body ground Always Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK SLIDING ROOF ECU (BATTERY VOLTAGE AND BODY GROUND)


    1. A01X09SE01
      *1 Front view of wire harness connector: (to Sliding Roof ECU)

      Disconnect the R5 ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      R5-2 (E) - Body ground Always Below 1 Ω
      Standard Voltage
      Tester Connection Condition Specified Condition
      R5-1 (B) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE SLIDING ROOF ECU


    1. Temporarily replace the sliding roof ECU with a new or normally functioning one Click here.

    2. Clear the DTC Click here.


    NEXT

  6. CHECK FOR DTC


    1. Recheck for DTCs Click here.

      Result
      Result Proceed to
      DTC B1273 is not output A
      DTC B1273 is output B

    A

    END (SLIDING ROOF ECU IS DEFECTIVE)

    B

    REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)