LIN COMMUNICATION SYSTEM, Diagnostic DTC:U1128

DTC Code DTC Name
U1128 Lost Communication with Front Climate Control Seat ECU RH

DESCRIPTION

This DTC is output when LIN communication between the front seat climate control ECU RH and outer mirror switch stops for 10 seconds or more.

DTC Code DTC Detection Condition Trouble Area
U1128 No communication between front seat climate control ECU RH and outer mirror switch for 10 seconds or more

  • Front seat climate control ECU RH

  • Outer mirror switch

  • Harness or connector

WIRING DIAGRAM

A000ZE8E11

CAUTION / NOTICE / HINT

Note


  • When using the intelligent tester with the power 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.

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

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. Clear the DTC Click here.


    NEXT

  2. CHECK FOR DTC


    1. Recheck for DTC Click here.

      Result:
      Result Proceed to
      DTC U1128 output reoccurs A
      DTC U1128 output does not reoccur B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  3. CHECK HARNESS AND CONNECTOR (OUTER MIRROR SWITCH - SEAT CLIMATE CONTROL ECU)

    A000XKNE02
    *1 Rear view of wire harness connector: (to Outer Mirror Switch)
    *2 Rear view of wire harness connector: (to Front Seat Climate Control ECU RH)

    1. Disconnect the L6 switch connector.

    2. Disconnect the e4 ECU connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L6-7 (MPX) - e4-13 (LIN) Always Below 1 Ω
      L6-7 (MPX) or e4-13 (LIN) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (SEAT CLIMATE CONTROL ECU - BATTERY AND BODY GROUND)


    1. A000VZEE01
      *1 Front view of wire harness connector: (to Front Seat Climate Control ECU RH)
      *2 VER

      Disconnect the e4 ECU connector.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      e4-1 (IG) - Body ground Power switch off Below 1 V
      e4-1 (IG) - Body ground Power switch on (IG) 11 to 14 V
      e4-2 (SYSB) - Body ground Always 11 to 14 V
      Standard resistance
      Tester Connection Condition Specified Condition
      e4-11 (VER) - Body ground Always Below 1 Ω
      e4-12 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK FRONT SEAT CLIMATE ECU RH (OPERATION)


    1. Temporarily replace the front seat climate ECU RH with a new or normally functioning one Click here.

    2. Clear the DTC Click here.


    NEXT

  6. CHECK FOR DTC


    1. Recheck for DTC Click here.

      Result:
      Result Proceed to
      DTC U1128 output does not reoccur A
      DTC U1128 output reoccurs B

    A

    END (FRONT SEAT CLIMATE CONTROL ECU RH IS DEFECTIVE)

    B

    REPLACE OUTER MIRROR SWITCH Click here