LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2009 >> LX 570 >> Repair and Diagnosis >> Body & Frame >> Seats >> Power Seat Control System (Diagnostics) >> Front Power Seat Control System >> Power Seat Position is not Memorized >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Power Seat Position is not Memorized: Procedure

  1. CHECK FRONT POWER SEAT CONTROL FUNCTION 
    1. Check that each function of the power seat operates normally by using the front power seat switches.

      OK

      Each function of power seat operates normally by using seat switches.

    NG → See step   9 

    OK: Go to next step 

  2. CHECK SEAT MEMORY SWITCH FUNCTION 
    1. Perform a memory operation properly. Check that the buzzer sounds to indicate the completion of the memory operation.
      NOTE:
      • The seat position will not be recorded if the seat memory SET switch and 2 or more of the seat memory switches (for example, seat memory switch 1 and seat memory switch 2) 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 memory switch function operates normally.

    NG → See step   3 

    OK → END 

  3. CHECK COMBINATION METER FUNCTION 
    1. When the engine switch is on (IG) and the shift lever is in P, check that the combination meter shows that the shift lever is in P.

      OK

      Meter shows that shift lever is in P.

    NG → See step   10 

    OK: Go to next step 

  4. READ VALUE USING TECHSTREAM (SEAT MEMORY SWITCH) 
    1. Check the Data List for proper functioning of the seat memory switch.
      DRIVER SEAT

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      SET Switch Seat memory SET switch signal / ON or OFF ON: Seat memory SET switch on
      OFF: Seat memory SET switch off
      -
      M1 Switch Seat memory switch 1 signal / ON or OFF ON: Seat memory switch 1 on
      OFF: Seat memory switch 1 off
      -
      M2 Switch Seat memory switch 2 signal / ON or OFF ON: Seat memory switch 2 on
      OFF: Seat memory switch 2 off
      -
      M3 Switch Seat memory switch 3 signal / ON or OFF ON: Seat memory switch 3 on
      OFF: Seat memory switch 3 off
      -

      OK

      On the Techstream screen, each item changes between ON and OFF according to above chart.

    NG → See step   5 

    OK → See step   11 

  5. INSPECT SEAT MEMORY SWITCH 
    Fig 1: Identifying Seat Memory Switch Connector
    GTY114739Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the seat memory switch. Refer to REMOVAL .
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      4 (M1) - 7 (E) Seat memory switch 1 pressed Below 1 Ω
      2 (M2) - 7 (E) Seat memory switch 2 pressed Below 1 Ω
      1 (M3) - 7 (E) Seat memory switch 3 pressed Below 1 Ω
      5 (MRY) - 7 (E) Seat memory SET switch pressed Below 1 Ω

    NG → See step   12 

    OK: Go to next step 

  6. CHECK HARNESS AND CONNECTOR (OUTER MIRROR CONTROL ECU - SEAT MEMORY SWITCH) 
    Fig 2: Identifying X1 Switch And 118 ECU Connectors
    GTY114740Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the I18 ECU connector.
    2. Disconnect the X1 switch connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      I18-8 (M1) - X1-4 (M1) Always Below 1 Ω
      I18-7 (M2) - X1-2 (M2) Always Below 1 Ω
      I18-6 (M3) - X1-1 (M3) Always Below 1 Ω
      I18-9 (MM) - X1-5 (MRY) Always Below 1 Ω
      I18-10 (MSWE) - X1-7 (E) Always Below 1 Ω
      I18-8 (M1) - Body ground Always 10 kΩ or higher
      I18-7 (M2) - Body ground Always 10 kΩ or higher
      I18-6 (M3) - Body ground Always 10 kΩ or higher
      I18-9 (MM) - Body ground Always 10 kΩ or higher
      I18-10 (MSWE) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  7. CHECK OUTER MIRROR CONTROL ECU (OPERATION) 
    1. After replacing the outer mirror control ECU, check that the front power seat control functions operate normally using the front seat switches and seat memory switch.

      OK

      Front power seat control functions operate normally.

    NG → See step   11 

    OK → See step   8 

  8. END (REPLACE OUTER MIRROR CONTROL ECU). Refer to  REMOVAL 
  9. GO TO PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE  
  10. GO TO METER / GAUGE SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
  11. REPLACE POSITION CONTROL ECU AND SWITCH. Refer to  REMOVAL 
  12. REPLACE SEAT MEMORY SWITCH. Refer to  REMOVAL