FRONT POWER SEAT CONTROL SYSTEM Power Seat Position is not Memorized

DESCRIPTION

The main body ECU (multiplex network body ECU) receives seat memory switch (driver door) signals from the outer mirror control ECU assembly (driver door) via CAN communication. If the seat memory SET switch is being pressed when one of the M1, M2 or M3 switches is pressed, or if one of the M1, M2 or M3 switches is pressed within 3 seconds of pressing the seat memory SET switch, the main body ECU (multiplex network body ECU) sends a memory request signal to the position control ECU and switch assembly (driver seat). After receiving the request signal, the position control ECU and switch assembly (driver seat) memorizes the location data of each motor.

WIRING DIAGRAM

B007808E08

CAUTION / NOTICE / HINT

Note


  • The seat position will not be stored if the SET switch and 2 or more of the seat memory switches (for example, M1 switch and M2 switch) are pressed simultaneously.

    If a memorizing operation has failed, release all switches. The seat memory function does not operate unless the switches are released.

  • The seat will not return to the memorized position if 2 or more of the seat memory switches (for example, M1 switch and M2 switch) are pressed simultaneously.

    If a restoring operation has failed, release all switches. The seat memory restoring function does not operate unless the switches are released.

  • The front power seat control system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

    Click here

  • Before replacing the main body ECU (multiplex network body ECU), refer to Service Bulletin.

PROCEDURE


  1. CHECK FRONT POWER SEAT CONTROL OPERATION


    1. Check that each function of the power seat operates normally by using the position control ECU and switch assembly (driver seat).

      Click here

      OK
      Each function of the power seat operates normally using the position control ECU and switch assembly (driver seat).
      Result
      Proceed to
      OK
      NG

    NG

    GO TO PROBLEM SYMPTOMS TABLE Click here

    OK

  2. READ VALUE USING GTS (SEAT MEMORY SWITCH (DRIVER DOOR))


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Mirror L*1 or Mirror R*2 / Data List.


      • *1: for LHD

      • *2: for RHD

    5. Read the Data List according to the display on the GTS.


      Body Electrical > Mirror L > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Seat Memory Switch1 M1 switch ON or OFF

      ON: M1 switch on

      OFF: M1 switch off

      		 -
      Seat Memory Switch2 M2 switch ON or OFF

      ON: M2 switch on

      OFF: M2 switch off

      		 -
      Seat Memory Switch3 M3 switch ON or OFF

      ON: M3 switch on

      OFF: M3 switch off

      		 -
      Seat Memory Set SW SET switch ON or OFF

      ON: SET switch on

      OFF: SET switch off

      		 -

      Body Electrical > Mirror L > Data List
      Tester Display
      Seat Memory Switch1
      Seat Memory Switch2
      Seat Memory Switch3
      Seat Memory Set SW

      Body Electrical > Mirror R > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Seat Memory Switch1 M1 switch ON or OFF

      ON: M1 switch on

      OFF: M1 switch off

      		 -
      Seat Memory Switch2 M2 switch ON or OFF

      ON: M2 switch on

      OFF: M2 switch off

      		 -
      Seat Memory Switch3 M3 switch ON or OFF

      ON: M3 switch on

      OFF: M3 switch off

      		 -
      Seat Memory Set SW SET switch ON or OFF

      ON: SET switch on

      OFF: SET switch off

      		 -

      Body Electrical > Mirror R > Data List
      Tester Display
      Seat Memory Switch1
      Seat Memory Switch2
      Seat Memory Switch3
      Seat Memory Set SW
      OK
      ON or OFF is displayed on the GTS according to the table above.
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT SEAT MEMORY SWITCH (DRIVER DOOR) Click here

    OK

  3. PERFORM ACTIVE TEST USING GTS (BUZZER)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Driver Seat / Active Test.

    5. Read the Data List according to the display on the GTS.


      Body Electrical > Driver Seat > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Buzzer Buzzer operation OFF/ON -

      Body Electrical > Driver Seat > Active Test
      Tester Display
      Buzzer
      OK
      Buzzer sounds normally.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY (DRIVER SEAT) Click here

    OK

  4. REPLACE OUTER MIRROR CONTROL ECU ASSEMBLY (DRIVER DOOR)


    1. Temporarily replace the outer mirror control ECU assembly (driver door) with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK SEAT POSITION MEMORY AND RESTORING FUNCTION


    1. Check that the seat position memory and restoring function.

      Click here

      OK
      Seat position memory and restoring function operate normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (OUTER MIRROR CONTROL ECU ASSEMBLY (DRIVER DOOR) WAS DEFECTIVE)

    NG

  6. REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY (DRIVER SEAT)


    1. Temporarily replace the position control ECU and switch assembly (driver seat) with a new or known good one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK SEAT POSITION MEMORY AND RESTORING FUNCTION


    1. Check that the seat position memory and restoring function.

      Click here

      OK
      Seat position memory and restoring function operate normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (POSITION CONTROL ECU AND SWITCH ASSEMBLY (DRIVER SEAT) WAS DEFECTIVE)

    NG

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

  8. INSPECT SEAT MEMORY SWITCH (DRIVER DOOR)


    1. Remove the seat memory switch (driver door).

      Click here

    2. Inspect the seat memory switch (driver door).

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SEAT MEMORY SWITCH (DRIVER DOOR) Click here

    OK

  9. CHECK HARNESS AND CONNECTOR (OUTER MIRROR CONTROL ECU ASSEMBLY (DRIVER DOOR) - SEAT MEMORY SWITCH (DRIVER DOOR) - BODY GROUND)


    1. Disconnect the S12*1 or R12*2 outer mirror control ECU assembly (driver door) connector.


      • *1: for LHD

      • *2: for RHD

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      S12-1 (MM) - S5-4 (MMRY) Always Below 1 Ω
      S12-1 (MM) or S5-4 (MMRY) - Body ground Always 10 kΩ or higher
      S12-2 (M1) - S5-1 (1) Always Below 1 Ω
      S12-2 (M1) or S5-1 (1) - Body ground Always 10 kΩ or higher
      S12-3 (M2) - S5-2 (2) Always Below 1 Ω
      S12-3 (M2) or S5-2 (2) - Body ground Always 10 kΩ or higher
      S12-4 (M3) - S5-3 (3) Always Below 1 Ω
      S12-4 (M3) or S5-3 (3) - Body ground Always 10 kΩ or higher
      S12-7 (GND) - Body ground Always Below 1 Ω
      S5-5 (E) - Body ground Always Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition
      R12-1 (MM) - R5-4 (MRY) Always Below 1 Ω
      R12-1 (MM) or R5-4 (MRY) - Body ground Always 10 kΩ or higher
      R12-2 (M1) - R5-1 (M1) Always Below 1 Ω
      R12-2 (M1) or R5-1 (M1) - Body ground Always 10 kΩ or higher
      R12-3 (M2) - R5-2 (M2) Always Below 1 Ω
      R12-3 (M2) or R5-2 (M2) - Body ground Always 10 kΩ or higher
      R12-4 (M3) - R5-3 (M3) Always Below 1 Ω
      R12-4 (M3) or R5-3 (M3) - Body ground Always 10 kΩ or higher
      R12-7 (GND) - Body ground Always Below 1 Ω
      R5-5 (E) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE OUTER MIRROR CONTROL ECU ASSEMBLY (DRIVER DOOR) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR