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LIN COMMUNICATION SYSTEM, Diagnostic DTC:B1273

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DTC Code DTC Name
B1273 Sliding Roof ECU Communication Stop
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DESCRIPTION

This DTC is stored when LIN communication between the sliding roof drive gear and main body ECU (instrument panel junction block assembly) stops for 10 seconds or more.

DTC Code DTC Detection Condition Trouble Area
B1273 No communication between the sliding roof drive gear and main body ECU (instrument panel junction block assembly) for 10 seconds or more.

  • Sliding roof drive gear sub-assembly

  • Main body ECU (instrument panel junction block assembly)

  • Harness or connector
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WIRING DIAGRAM

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INSPECTION PROCEDURE

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 sliding roof drive gear and main body ECU (instrument panel junction block assembly) stops, DTC B2325 is also stored.

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PROCEDURE


  1. Click here

    CLEAR DTC


    1. Clear the DTCs (Click here).


  2. Click here

    CHECK FOR DTC


    1. Check for DTCs (Click here).

      Table 1. Result
      Result Proceed to
      DTC B1273 is output A
      DTC B1273 is not output B

  3. Click here

    CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SLIDING ROOF DRIVE GEAR)


    1. Disconnect the H79 ECU connector.

    2. Disconnect the z3 drive gear connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H79-23 (LIN2) - z3-4 Always Below 1 Ω
      H79-23 (LIN2) - 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 Sliding Roof Drive Gear)

  4. Click here

    CHECK HARNESS AND CONNECTOR (SLIDING ROOF DRIVE GEAR - BATTERY AND BODY GROUND)


    1. A01IN8ME08

      Disconnect the z3 drive gear connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z3-2 - Body ground Always Below 1 Ω
      Standard Voltage
      Tester Connection Condition Specified Condition
      z3-1 - Body ground Always 11 to 14 V
      Table 3. Text in Illustration
      *1

      Front view of wire harness connector

      (to Sliding Roof Drive Gear)

  5. Click here

    REPLACE SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY


    1. Temporarily replace the sliding roof drive gear with a new or normally functioning one (Click here).

    2. Clear the DTCs (Click here).


  6. Click here

    CHECK FOR DTC


    1. Check for DTCs (Click here).

      Table 4. Result
      Result Proceed to
      DTC B1273 is not output A
      DTC B1273 is output B

  7. Click here

    USE SIMULATION METHOD TO CHECKClick here

  8. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  9. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  10. Click here

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

  11. Click here

    END (SLIDING ROOF DRIVE GEAR IS DEFECTIVE)