LIN COMMUNICATION SYSTEM, Diagnostic DTC:U1131

DTC Code DTC Name
U1131 Lost Communication with Rear Climate Control Seat ECU LH

DESCRIPTION

This DTC is output when LIN communication between the rear seat climate control ECU LH and rear power seat module switch stops for 10 seconds or more.

DTC Code DTC Detection Condition Trouble Area
U1131 No communication between rear seat climate control ECU LH and rear power seat module switch for 10 seconds or more

  • Rear seat climate control ECU LH

  • Rear power seat module switch

  • Wire harness

Tech Tips

For vehicles with seat heater system only.

WIRING DIAGRAM

A01GHSTE17

INSPECTION PROCEDURE

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.

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

Tech Tips

When DTC U0211, U0246, U1130 and U1131 are output simultaneously, perform troubleshooting for "Rear 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 U1131 output reoccurs A
      DTC U1131 output does not reoccur B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  3. CHECK HARNESS OR CONNECTOR (REAR POWER SEAT SWITCH - SEAT CLIMATE CONTROL ECU LH)


    1. w/ Climate Control Seat System:


      1. Disconnect the r2*1 or S15*2 module switch connector.

        Tech Tips

        *1: except 4-Passenger with Ottoman

        *2: for 4-Passenger with Ottoman

        A01GJL3E26

      2. Disconnect the f28 ECU connector.

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

        Standard resistance
        except 4-Passenger with Ottoman:
        Tester Connection Condition Specified Condition
        r2-12 (MPX) - f28-13 (LIN) Always Below 1 Ω
        r2-12 (MPX) or f28-13 (LIN) - Body ground Always 10 kΩ or higher
        for 4-Passenger with Ottoman:
        Tester Connection Condition Specified Condition
        S15-5 (MPX) - f28-13 (LIN) Always Below 1 Ω
        S15-5 (MPX) or f28-13 (LIN) - Body ground Always 10 kΩ or higher
        Standard voltage
        except 4-Passenger with Ottoman:
        Tester Connection Switch Condition Specified Condition
        r2-12 (MPX) - f28-13 (LIN) Engine switch on (IG) Below 1 V
        for 4-Passenger with Ottoman:
        Tester Connection Switch Condition Specified Condition
        S15-5 (MPX) - f28-13 (LIN) Engine switch on (IG) Below 1 V

    2. w/ Seat Heater System:


      1. Disconnect the r2*1 or S15*2 module switch connector.

        Tech Tips

        *1: except 4-Passenger with Ottoman

        *2: for 4-Passenger with Ottoman

        A01GJL3E27

      2. Disconnect the f13 ECU connector.

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

        Standard resistance
        except 4-Passenger with Ottoman:
        Tester Connection Condition Specified Condition
        r2-12 (MPX) - f13-13 (LIN) Always Below 1 Ω
        r2-12 (MPX) or f13-13 (LIN) - Body ground Always 10 kΩ or higher
        for 4-Passenger with Ottoman:
        Tester Connection Condition Specified Condition
        S15-5 (MPX) - f13-13 (LIN) Always Below 1 Ω
        S15-5 (MPX) or f13-13 (LIN) - Body ground Always 10 kΩ or higher
        Standard voltage
        except 4-Passenger with Ottoman:
        Tester Connection Switch Condition Specified Condition
        r2-12 (MPX) - f13-13 (LIN) Engine switch on (IG) Below 1 V
        for 4-Passenger with Ottoman:
        Tester Connection Switch Condition Specified Condition
        S15-5 (MPX) - f13-13 (LIN) Engine switch on (IG) Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK REAR SEAT CLIMATE CONTROL ECU LH (BATTERY VOLTAGE AND GROUND)


    1. w/ Climate Control Seat System:


      1. Disconnect the f28 ECU connector.

        A01GIIJE07

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

        Standard resistance
        Tester Connection Condition Specified Condition
        f28-12 (GND) - Body ground Always Below 1 Ω
        Standard voltage
        Tester Connection Condition Specified Condition
        f28-1 (IG) - Body ground Engine switch off Below 1 V
        f28-1 (IG) - Body ground Engine switch on (IG) 11 to 14 V
        f28-2 (SYSB) - Body ground Always 11 to 14 V

    2. w/ Seat Heater System:


      1. Disconnect the f13 ECU connector.

        A01GIIJE10

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

        Standard resistance
        Tester Connection Condition Specified Condition
        f13-12 (GND) - Body ground Always Below 1 Ω
        Standard voltage
        Tester Connection Condition Specified Condition
        f13-1 (IG) - Body ground Engine switch off Below 1 V
        f13-1 (IG) - Body ground Engine switch on (IG) 11 to 14 V
        f13-2 (SYSB) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE REAR SEAT CLIMATE CONTROL ECU LH


    1. Temporarily replace the rear seat climate control ECU LH 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 U1131 output does not reoccur A
      DTC U1131 output reoccurs (for fixed seat type) B
      DTC U1131 output reoccurs (for power seat) C
      DTC U1131 output reoccurs (for 4-Passenger with Ottoman) D
      DTC U1131 output reoccurs (for 5-Passenger with Ottoman) E

    B

    REPLACE REAR POWER SEAT MODULE SWITCH Click here

    C

    REPLACE REAR POWER SEAT MODULE SWITCH Click here

    D

    REPLACE REAR POWER SEAT MODULE SWITCH Click here

    E

    REPLACE REAR POWER SEAT MODULE SWITCH Click here

    A

    END (REAR SEAT CLIMATE CONTROL ECU LH IS DEFECTIVE)