LIN COMMUNICATION SYSTEM, Diagnostic DTC:U1127

DTC Code DTC Name
U1127 Lost Communication with Center Console Switch ECU

DESCRIPTION

This DTC is output when LIN communication between the outer mirror switch and No. 1 console switch stops for 10 seconds or more.

DTC Code DTC Detection Condition Trouble Area
U1127 No communication between outer mirror switch and No. 1 console switch for 10 seconds or more

  • No. 1 console switch

  • Outer mirror switch

  • Wire harness

WIRING DIAGRAM

A001BL7E05

CAUTION / NOTICE / HINT

Note

When using the intelligent tester with the engine 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 tester and vehicle begins.

Tech Tips

When DTC U1127, U1128 and U1129 are output simultaneously, perform troubleshooting for "Driver Side Switch Module LIN Communication Malfunction" first Click here.

PROCEDURE


  1. CLEAR DTC


    1. Delete the DTC Click here.


    NEXT

  2. CHECK FOR DTC


    1. Recheck for DTC Click here.

      Result:
      Result Proceed to
      DTC U1127 output reoccurs A
      DTC U1127 output does not reoccur B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  3. CHECK HARNESS AND CONNECTOR (OUTER MIRROR SWITCH - NO.1 CONSOLE SWITCH)

    A001C71E01
    *1 Rear view of wire harness connector: (to Outer Mirror Switch)
    *2 Rear view of wire harness connector: (to No. 1 Console Switch)

    1. Disconnect the L6 and L75 switch connectors.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L6-7 (MPX) - L75-3 (MPX) Always Below 1 Ω
      L6-7 (MPX) - Body ground Always 10 kΩ or higher
      Standard voltage
      Tester Connection Switch Condition Specified Condition
      L6-7 (MPX) - Body ground Engine switch on (IG) Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK NO. 1 CONSOLE SWITCH (BATTERY VOLTAGE AND GROUND)


    1. A001F59E01
      *1 Front view of wire harness connector: (to No. 1 Console Switch)

      Disconnect the L75 switch connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L75-5 (E) - Body ground Always Below 1 Ω
      Standard voltage
      Tester Connection Condition Specified Condition
      L75-1 (B) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE NO. 1 CONSOLE SWITCH


    1. Temporarily replace the No. 1 console switch with a new or normally functioning one.


    NEXT

  6. CHECK FOR DTC


    1. Delete the DTC Click here.

    2. Recheck for DTC Click here.

      Result:
      Result Proceed to
      DTC U1127 output does not reoccur A
      DTC U1127 output reoccurs B

    A

    END (NO. 1 CONSOLE SWITCH IS DEFECTIVE)

    B

    REPLACE OUTER MIRROR SWITCH Click here