LIN COMMUNICATION SYSTEM, Diagnostic DTC:B1273

DTC Code DTC Name
B1273 Sliding Roof ECU Communication Stop

DESCRIPTION

This DTC is output when LIN communication between the sliding roof drive gear sub-assembly and main body ECU (multiplex network body ECU) stops for 10 seconds or more.

DTC Code DTC Detection Condition Trouble Area
B1273 No communication between sliding roof drive gear sub-assembly and main body ECU (multiplex network body ECU) for 10 seconds or more

  • Main body ECU (multiplex network body ECU)

  • Cowl side junction block LH

  • Sliding roof drive gear sub-assembly

  • Harness or connector

Tech Tips

For vehicles with sliding roof system only.

WIRING DIAGRAM

A01FRB2E03

INSPECTION PROCEDURE

Note


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

    Connect the GTS to the vehicle, and turn a courtesy switch on and off at 1.5 seconds 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 the sliding roof drive gear sub-assembly is replaced or removed and reinstalled, it requires initialization (See page. Click here)

  • If the main body ECU (multiplex network body ECU) is replaced, refer to the Service Bulletin.

Tech Tips

DTC B2325 is output when the communication between all of the following components and main body ECU (multiplex network body ECU) stops.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check 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 [MULTIPLEX NETWORK BODY ECU] - SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY)


    1. Remove the main body ECU (multiplex network body ECU) from the cowl side junction block LH Click here.

    2. Disconnect the Y4 sliding roof drive gear sub-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) - Y4-11 (LIN) Always Below 1 Ω
      A-16 (LIN2) - Body ground Always 10 kΩ or higher

    NG

    CHECK HARNESS AND CONNECTOR (COWL SIDE JUNCTION BLOCK LH - SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY) Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY - BATTERY AND BODY GROUND)

    A01FU8LE01
    Text in Illustration
    *a

    Front view of wire harness connector

    (to Sliding Roof Drive Gear Sub-assembly)

    1. Disconnect the sliding roof drive gear sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Y4-12 (E) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Y4-8 (B) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY


    1. Temporarily replace the sliding roof drive gear sub-assembly with a new or normally functioning one Click here.


    NEXT

  6. CHECK FOR DTC


    1. Clear the DTC Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1273 is not output.

    NG

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

    OK

    END (SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY IS DEFECTIVE)

  7. CHECK HARNESS AND CONNECTOR (COWL SIDE JUNCTION BLOCK LH - SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY)


    1. Disconnect the 5A cowl side junction block LH connector.

    2. Disconnect the Y4 sliding roof drive gear sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      5A-50 - Y4-11 (LIN) Always Below 1 Ω
      5A-50 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE COWL SIDE JUNCTION BLOCK LH Click here