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Home >> Lexus >> 2005 >> SC 430 >> Repair and Diagnosis >> Body & Frame >> Seats >> Front Power Seat Control System (W/Memory) - Diagnostics >> Position Cannot Be Memorized >> Inspection Procedure
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Inspection 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. 

    1. NG: Go to  PROBLEM SYMPTOMS TABLE  
    2. OK: Go to next step. 
  2. CHECK SEAT MEMORY SWITCH FUNCTION (SEAT MEMORY FUNCTION) 
    1. Perform a memorizing operation properly, and then check whether the memory functions normally or the buzzer sounds to inform that the memorizing operation has been done.
      NOTE:
      • The memory does not function when the SET, M1 and M2 switches are simultaneously pressed.
      • If a memorizing operation has failed, release all switches. The seat memory function does not operate unless the switches are released.
    1. NG: Go to step   3 
    2. OK: NORMAL 
  3. READ DATA LIST (SEAT MEMORY SWITCH) 
    1. Check the DATA LIST for proper functioning of the front power seat switch, seat memory switch, unlock warning switch, front door courtesy lamp switch (driver side), ignition switch and PNP switch.

      Position control ECU assy (driver, passenger side): 

      Fig 1: Data List Table - Seat Memory Switch
      G02956876Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: 

      On tester screen, each item changes between ON, OFF and MEM and NOT MEM according to  Fig 1 . 

    1. NG: Go to step   4 
    2. OK: REPLACE POSITION CONTROL ECU ASSY 
  4. INSPECT SEAT MEMORY SWITCH 
    1. Measure the resistance of the switch.

      Standard: 

      SEAT MEMORY SWITCH

      Tester Connection Switch Condition Specified Condition
      1 - 3 M1 switch pressed Below 1 ohms
      1 - 4 M2 switch pressed Below 1 ohms
      1 - 2 SET switch pressed Below 1 ohms
      Fig 2: Inspecting Seat Memory Switch
      G02956877Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPLACE SEAT MEMORY SWITCH 
    2. OK: Go to next step. 
  5. CHECK WIRE HARNESS (SEAT MEMORY SWITCH - MULTIPLEX NETWORK DOOR ECU FRONT (DOOR ECU)) 
    1. Disconnect the D20 or S29 switch connector.
    2. Disconnect the D18 or P10 ECU connector.
    3. Measure the resistance of the wire harness side connectors.

      Standard: 

      Driver side 

      SEAT MEMORY SWITCH - MULTIPLEX NETWORK DOOR ECU FRONT (DOOR ECU) (DRIVER SIDE)

      Tester Connection Specified Condition
      D20-3 (M1) - D18-16 (M1) Below 1 ohms
      D20-4 (M2) - D18-15 (M2) Below 1 ohms
      D20-2 (MRY) - D18-24 (MM) Below 1 ohms
      D20-1 (E) - D18-23 (MSWE) Below 1 ohms

      Passenger side 

      SEAT MEMORY SWITCH - MULTIPLEX NETWORK DOOR ECU FRONT (DOOR ECU) (PASSENGER SIDE)

      Tester Connection Specified Condition
      S29-3 (M1) - P10-16 (M1) Below 1 ohms
      S29-4 (M2) - P10-15 (M2) Below 1 ohms
      S29-2 (MRY) - P10-24 (MM) Below 1 ohms
      S29-1 (E) - P10-23 (MSWE) Below 1 ohms
      Fig 3: Checking Wire Harness (Seat Memory Switch - Multiplex Network Door ECU Front (Door ECU))
      G02956878Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 
    2. OK: Go to next step. 
  6. REPLACE MULTIPLEX NETWORK DOOR ECU FRONT (DOOR ECU) 
    1. After replacing the multiplex network door ECU front, check that the front power seat control functions operate normally using front seat switches and seat memory switch.
    1. NG: REPLACE SEAT MEMORY SWITCH 
    2. OK: END (MULTIPLEX NETWORK DOOR ECU FRONT IS DEFECTIVE) 
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