FRONT POWER SEAT CONTROL SYSTEM(w/ Memory) Power Seat does not Return to Memorized Position

DESCRIPTION

When either the M1 or M2 switch is pressed, the outer mirror control ECU assembly (driver door) sends a switch signal to the main body ECU (multiplex network body ECU) via CAN communication. Then, the main body ECU (multiplex network body ECU) sends a recall request signal to the position control ECU and switch assembly. The position control ECU and switch assembly operates each motor to achieve each memorized position value.

WIRING DIAGRAM

A00290NE05

CAUTION / NOTICE / HINT

Note


  • The seat position will not be stored if the SET switch and 2 of the seat memory switches 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 of the seat memory switches 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 (w/ Memory) 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

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

  • As the door control battery is installed between the vehicle battery and main body ECU (multiplex network body ECU), first perform the inspections in On-Vehicle Inspection to confirm that there are no malfunctions in the power source circuit for the main body ECU (multiplex network body ECU) before performing this troubleshooting procedure.*

    Click here


    • *: for LHD

PROCEDURE


  1. CHECK FRONT POWER SEAT CONTROL OPERATION


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

      Click here

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

    NG

    GO TO PROBLEM SYMPTOMS TABLE Click here

    OK

  2. CHECK SEAT POSITION MEMORY FUNCTION


    1. Check that the seat position memory function.

      Click here

      OK
      Seat position memory function is normal.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO OTHER DIAGNOSIS PROCEDURE (Power Seat Position is not Memorized) Click here

    OK

  3. CHECK SEAT POSITION RESTORING FUNCTION


    1. Under each of the following conditions, check that the seat position restoring function operates by pressing the M1 or M2 switch.

      Click here


      • The engine switch is on (IG), and the shift lever is in P.*1

      • The engine switch is turned off within 180 seconds after the driver door is closed and opened.*2

      • The engine switch is turned off within 60 seconds after the driver door is opened and closed.*3

      Result
      Result Proceed to
      Seat position restoring function does not operate at all A
      Seat position restoring function does not operate when the condition is*1 B

      • Seat position restoring function does not operate when the condition is*2

      • Seat position restoring function does not operate when the condition is*3

      		 C

    B

    READ VALUE USING GTS (SHIFT P POSITION STATE) Click here

    C

    READ VALUE USING GTS (DRIVER DOOR COURTESY SWITCH) Click here

    A

  4. READ VALUE USING GTS (SEAT POSITION MEMORY)


    1. Store a seat position in memory for each of the M1 and M2 switches.

      Click here

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the GTS on.

    5. Enter the following menus: Body Electrical / Driver Seat / Data List.

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


      Body Electrical > Driver Seat > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Seat Memory No1 Seat position memorized with M1 switch Mem or Not Mem

      Mem: Memorized

      Not Mem: Not memorized

      		 -
      Seat Memory No2 Seat position memorized with M2 switch Mem or Not Mem

      Mem: Memorized

      Not Mem: Not memorized

      		 -

      Body Electrical > Driver Seat > Data List
      Tester Display
      Seat Memory No1
      Seat Memory No2
      OK
      Mem appears on the GTS screen.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO OTHER DIAGNOSIS PROCEDURE (Power Seat Position is not Memorized) Click here

    OK

  5. 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

  6. 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 operates normally.
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

  7. REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY


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

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  8. 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 operates normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (POSITION CONTROL ECU AND SWITCH ASSEMBLY WAS DEFECTIVE)

    NG

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

  9. READ VALUE USING GTS (SHIFT P POSITION STATE)


    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 / Data List.

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


      Body Electrical > Driver Seat > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      P Switch Park state signal ON or OFF

      ON: Shift lever in P

      OFF: Shift lever in a position other than P

      		 -

      Body Electrical > Driver Seat > Data List
      Tester Display
      P Switch
      OK
      On the GTS screen, the item changes between ON and OFF according to the above.
      Result
      Result Proceed to
      OK A
      NG (for U760E) B
      NG (for UA80E or UA80F) C

    A

    REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY Click here

    B

    GO TO AUTOMATIC TRANSAXLE SYSTEM (P0705) for U760E: Click here

    C

    GO TO AUTOMATIC TRANSAXLE SYSTEM (P070513) for UA80E: Click here
    GO TO AUTOMATIC TRANSAXLE SYSTEM (P070513) for UA80F: Click here

  10. READ VALUE USING GTS (DRIVER DOOR COURTESY SWITCH)


    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 / Main Body / Data List.

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


      Body Electrical > Main Body > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      FR Door Courtesy SW Front door courtesy light switch assembly (driver door) signal*2 ON or OFF

      ON: Driver door open

      OFF: Driver door closed

      		 -
      FL Door Courtesy SW Front door courtesy light switch assembly (driver door) signal*1 ON or OFF

      ON: Driver door open

      OFF: Driver door closed

      		 -

      • *1: for LHD

      • *2: for RHD


      Body Electrical > Main Body > Data List
      Tester Display
      FR Door Courtesy SW
      FL Door Courtesy SW
      OK
      On the GTS screen, the item changes between ON and OFF according to the above.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY Click here

    NG

    GO TO LIGHTING SYSTEM (Front Door Courtesy Switch Circuit) Click here