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 (sliding roof drive gear sub-assembly) and main body ECU (multiplex network body ECU) stops for 10 seconds or more.

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

  • Sliding roof ECU (sliding roof drive gear sub-assembly)

  • Main body ECU (multiplex network body ECU)

  • Instrument panel junction block assembly

  • Wire harness or connector

  • S/ROOF fuse

WIRING DIAGRAM

A01JCM5E28

INSPECTION PROCEDURE

Note


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

  • When the sliding roof ECU (sliding roof drive gear sub-assembly) is replaced or removed and reinstalled, it requires initialization Click here.

  • When using the intelligent tester to troubleshoot with the power switch off:

    Connect the intelligent tester to the DLC3, and turn the courtesy switch on and off at 1.5-second intervals until communication between the intelligent tester and vehicle begins.

PROCEDURE


  1. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. Remove the instrument panel junction block assembly Click here.

      A01J8RZE04

    2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

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

      Tech Tips

      This inspection is to check the LIN line in the instrument panel junction block assembly that connects the wire harness to the built-in main body ECU (multiplex network body ECU).

      Standard Resistance
      Tester Connection Condition Specified Condition
      2A-27 (LIN2)- MB-16 (LIN2) Always Below 1 Ω
      2A-27 (LIN2) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 *2

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    OK

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


    1. A01JBVAE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Instrument Panel Junction Block Assembly)
      *2

      Front view of wire harness connector

      (to Sliding Roof ECU (Sliding Roof Drive Gear Sub-assembly))

      Disconnect the R23 sliding roof ECU (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
      2A-27 (LIN2) - R23-4 (MPX1) Always Below 1 Ω
      2A-27 (LIN2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (SLIDING ROOF ECU - BATTERY, BODY GROUND)


    1. A01JANDE11
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Sliding Roof ECU (Sliding Roof Drive Gear Sub-assembly))

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      R23-1 (B) - R23-2 (E) Power switch off 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      R23-2 (E) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE SLIDING ROOF ECU (SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY)


    1. Replace the sliding roof ECU (sliding roof drive gear sub-assembly) Click here.


    NEXT

  5. CHECK DTC OUTPUT


    1. Clear the DTC Click here.

    2. Recheck for DTCs.

      OK
      DTC B1273 is not output.

    NG

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

    OK

    END (SLIDING ROOF ECU WAS DEFECTIVE)