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 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

WIRING DIAGRAM

B173719E49

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 sliding roof drive gear 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 B1273 is output

      A

      DTC B1273 is not output

      B

    USE SIMULATION METHOD TO CHECK

    (Click here)

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

    U123789E02

    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)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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

    1. U122374E02

      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)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. 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. 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

    END (SLIDING ROOF DRIVE GEAR IS DEFECTIVE)

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)