FRONT POWER SEAT CONTROL SYSTEM (for LHD) Power Seat Position is not Memorized

DESCRIPTION

The main body ECU (multiplex network body ECU) receives seat memory switch signals from the outer mirror control ECU assembly (for driver side) 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 power seat switch assembly*1 or position control ECU assembly*2, *3. After receiving the request signal, the power seat switch assembly*1 or position control ECU assembly*2, *3 memorizes the location data of each motor.


WIRING DIAGRAM


  1. for Driver Side (Standard Seat Type):

    A01FS7IE08

  2. for Driver Side (Sports Seat Type, Luxury Seat Type):

    A01FS7IE09

  3. for Front Passenger Seat Type (Luxury Seat Type):

    A01FUJ2E05

INSPECTION PROCEDURE

Note


  • The seat position will not be recorded 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.

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

  • If the main body ECU (multiplex network body ECU) is replaced, refer to the Service Bulletin.

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Use the GTS to check if the CAN communication system is functioning normally Click here.

      OK
      CAN communication system DTC is not output.

    NG

    GO TO CAN COMMUNICATION SYSTEM Click here

    OK

  2. CHECK FRONT POWER SEAT CONTROL SYSTEM


    1. Check that each function of the power seat operates normally by using the power seat switch Click here.

      OK
      Each function of the power seat operates normally by using the power seat switch.
      Result
      Result Proceed to
      OK (for Driver Seat) A
      OK (for Front Passenger Seat) B
      NG C

    B

    READ VALUE USING GTS (SEAT MEMORY SWITCH) Click here

    C

    GO TO PROBLEM SYMPTOMS TABLE Click here

    A

  3. READ VALUE USING GTS (SEAT MEMORY SWITCH)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Front Left Door / Data List.

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

      Front Left Door
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Seat Memory Set SW SET switch signal / ON or OFF

      ON: SET switch on

      OFF: SET switch off

      		 -
      Seat Memory Switch 1 M1 switch signal / ON or OFF

      ON: M1 switch on

      OFF: M1 switch off

      		 -
      Seat Memory Switch 2 M2 switch signal / ON or OFF

      ON: M2 switch on

      OFF: M2 switch off

      		 -
      Seat Memory Switch 3 M3 switch signal / ON or OFF

      ON: M3 switch on

      OFF: M3 switch off

      		 -
      OK
      ON or OFF is displayed on the GTS according to the table above.

    NG

    INSPECT SEAT MEMORY SWITCH Click here

    OK

  4. PERFORM ACTIVE TEST USING GTS (BUZZER)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

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

    5. Perform the Active Test according to the display on the GTS.

      Driver Seat
      Tester Display Test Part Control Range Diagnostic Note
      Buzzer Buzzer operation ON / OFF -
      OK
      Buzzer sounds normally.
      Result
      Result Proceed to
      OK A
      NG (for Standard Seat Type) B
      NG (for Sports Seat Type) C
      NG (for Luxury Seat Type) D

    B

    REPLACE POWER SEAT SWITCH ASSEMBLY Click here

    C

    REPLACE POSITION CONTROL ECU ASSEMBLY Click here

    D

    REPLACE POSITION CONTROL ECU ASSEMBLY Click here

    A

  5. REPLACE FRONT MULTIPLEX NETWORK DOOR ECU LH


    1. Temporarily replace the front multiplex network door ECU LH with a new or normally functioning one Click here.


    NEXT

  6. CHECK SEAT POSITION MEMORY FUNCTION


    1. Perform a memory operation and check that the buzzer sounds to indicate the completion of the memory operation Click here.

      Note


      • The seat position will not be recorded 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.

      OK
      Seat position memory function operates normally.
      Result
      Result Proceed to
      OK A
      NG (for Standard Seat Type) B
      NG (for Sports Seat Type, Luxury Seat Type) C

    B

    REPLACE POWER SEAT SWITCH ASSEMBLY Click here

    C

    REPLACE POSITION CONTROL ECU ASSEMBLY Click here

    A

    END (FRONT MULTIPLEX NETWORK DOOR ECU LH WAS DEFECTIVE)

  7. REPLACE POWER SEAT SWITCH ASSEMBLY


    1. Temporarily replace the power seat switch assembly with a new or normally functioning one Click here.


    NEXT

  8. CHECK SEAT POSITION MEMORY FUNCTION


    1. Perform a memory operation and check that the buzzer sounds to indicate the completion of the memory operation Click here.

      Note


      • The seat position will not be recorded 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.

      OK
      Seat position memory function operates normally.

    NG

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

    OK

    END (POWER SEAT SWITCH ASSEMBLY WAS DEFECTIVE)

  9. REPLACE POSITION CONTROL ECU ASSEMBLY


    1. Temporarily replace the position control ECU assembly with a new or normally functioning one.



    NEXT

  10. CHECK SEAT POSITION MEMORY FUNCTION


    1. Perform a memory operation and check that the buzzer sounds to indicate the completion of the memory operation Click here.

      Note


      • The seat position will not be recorded 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.

      OK
      Seat position memory function operates normally.

    NG

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

    OK

    END (POSITION CONTROL ECU ASSEMBLY WAS DEFECTIVE)

  11. INSPECT SEAT MEMORY SWITCH


    1. A01FUVDE02
      Text in Illustration
      *a

      Component without harness connected

      (Seat Memory Switch)

      Remove the seat memory switch Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 (MMRY) - 5 (E) SET switch is pressed Below 1 Ω
      2 (1) - 5 (E) M1 switch is pressed Below 1 Ω
      3 (2) - 5 (E) M2 switch is pressed Below 1 Ω
      4 (3) - 5 (E) M3 switch is pressed Below 1 Ω
      1 (MMRY) - 5 (E) SET switch is not pressed 10 kΩ or higher
      2 (1) - 5 (E) M1 switch is not pressed 10 kΩ or higher
      3 (2) - 5 (E) M2 switch is not pressed 10 kΩ or higher
      4 (3) - 5 (E) M3 switch is not pressed 10 kΩ or higher

    NG

    REPLACE SEAT MEMORY SWITCH Click here

    OK

  12. CHECK HARNESS AND CONNECTOR (FRONT MULTIPLEX NETWORK DOOR ECU LH - SEAT MEMORY SWITCH)


    1. Disconnect the Q19 front multiplex network door ECU LH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q28-1 (MMRY) - Q19-25 (MM) Always Below 1 Ω
      Q28-2 (1) - Q19-22 (M1) Always Below 1 Ω
      Q28-3 (2) - Q19-23 (M2) Always Below 1 Ω
      Q28-4 (3) - Q19-24 (M3) Always Below 1 Ω
      Q28-5 (E) - Q19-26 (MSWE) Always Below 1 Ω
      Q19-25 (MM) - Body ground Always 10 kΩ or higher
      Q19-22 (M1) - Body ground Always 10 kΩ or higher
      Q19-23 (M2) - Body ground Always 10 kΩ or higher
      Q19-24 (M3) - Body ground Always 10 kΩ or higher
      Q19-26 (MSWE) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE FRONT MULTIPLEX NETWORK DOOR ECU LH Click here

  13. READ VALUE USING GTS (SEAT MEMORY SWITCH)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Front Right Door / Data List

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

      Front Right Door
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Seat Memory Set SW SET switch signal / ON or OFF

      ON: SET switch on

      OFF: SET switch off

      		 -
      Seat Memory Switch 1 M1 switch signal / ON or OFF

      ON: M1 switch on

      OFF: M1 switch off

      		 -
      Seat Memory Switch 2 M2 switch signal / ON or OFF

      ON: M2 switch on

      OFF: M2 switch off

      		 -
      Seat Memory Switch 3 M3 switch signal / ON or OFF

      ON: M3 switch on

      OFF: M3 switch off

      		 -
      OK
      ON or OFF is displayed on the GTS according to the table above.

    NG

    INSPECT SEAT MEMORY SWITCH Click here

    OK

  14. PERFORM ACTIVE TEST USING GTS (BUZZER)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

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

    5. Perform the Active Test according to the display on the GTS.

      Passenger Seat
      Tester Display Test Part Control Range Diagnostic Note
      Buzzer Buzzer operation ON / OFF -
      OK
      Buzzer sounds normally.

    NG

    REPLACE POSITION CONTROL ECU ASSEMBLY Click here

    OK

  15. REPLACE FRONT MULTIPLEX NETWORK DOOR ECU RH


    1. Temporarily replace the front multiplex network door ECU RH with a new or normally functioning one Click here.


    NEXT

  16. CHECK SEAT POSITION MEMORY FUNCTION


    1. Perform a memory operation and check that the buzzer sounds to indicate the completion of the memory operation Click here.

      Note


      • The seat position will not be recorded 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.

      OK
      Seat position memory function operates normally.

    NG

    REPLACE POSITION CONTROL ECU ASSEMBLY Click here

    OK

    END (FRONT MULTIPLEX NETWORK DOOR ECU RH WAS DEFECTIVE)

  17. INSPECT SEAT MEMORY SWITCH


    1. A01FUVDE01
      Text in Illustration
      *a

      Component without harness connected

      (Seat Memory Switch)

      Remove the seat memory switch Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 (MRY) - 5 (E) SET switch is pressed Below 1 Ω
      2 (M1) - 5 (E) M1 switch is pressed Below 1 Ω
      3 (M2) - 5 (E) M2 switch is pressed Below 1 Ω
      4 (M3) - 5 (E) M3 switch is pressed Below 1 Ω
      1 (MRY) - 5 (E) SET switch is not pressed 10 kΩ or higher
      2 (M1) - 5 (E) M1 switch is not pressed 10 kΩ or higher
      3 (M2) - 5 (E) M2 switch is not pressed 10 kΩ or higher
      4 (M3) - 5 (E) M3 switch is not pressed 10 kΩ or higher

    NG

    REPLACE SEAT MEMORY SWITCH Click here

    OK

  18. CHECK HARNESS AND CONNECTOR (FRONT MULTIPLEX NETWORK DOOR ECU RH - SEAT MEMORY SWITCH)


    1. Disconnect the Q4 front multiplex network door ECU RH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q13-1 (MRY) - Q4-25 (MM) Always Below 1 Ω
      Q13-2 (M1) - Q4-22 (M1) Always Below 1 Ω
      Q13-3 (M2) - Q4-23 (M2) Always Below 1 Ω
      Q13-4 (M3) - Q4-24 (M3) Always Below 1 Ω
      Q13-5 (E) - Q4-26 (MSWE) Always Below 1 Ω
      Q4-25 (MM) - Body ground Always 10 kΩ or higher
      Q4-22 (M1) - Body ground Always 10 kΩ or higher
      Q4-23 (M2) - Body ground Always 10 kΩ or higher
      Q4-24 (M3) - Body ground Always 10 kΩ or higher
      Q4-26 (MSWE) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE FRONT MULTIPLEX NETWORK DOOR ECU RH Click here