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Inspection Procedure

  1. READ VALUE OF HAND-HELD TESTER 
    1. Connect the hand-held tester (with CAN VIM) to the DLC3.
    2. Turn the ignition switch ON and press the hand-held tester main switch ON.
    3. Select the items below in the DATA LIST, and read the hand-held tester's screen.
    4. Watch the hand-held tester screen while adjusting the seat with the power seat control switches. Check that the position sensor value changes.
    5. Watch the hand-held tester screen while adjusting the seat with the power seat control switches. Check that the motor status changes from STANDBY to MOVING.

    HINT:

    When the seat is at an extreme position (for example, seatback position fully forward or sliding position fully rearward) and the power seat control switch is held down, the motor status should read LOCK. When the switch is released, the motor status should change to STANDBY.

    Driver seat ECU: 

    Fig 1: Driver Seat ECU - Data List Chart
    G03000980Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    Position sensor values should vary within the minimum and maximum values shown in the chart above. 

    For the tester's motor status item, the display should change between STANDBY, MOVING and LOCK according to the chart above. 

    NG: Go to step 2 

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON  PROBLEM SYMPTOMS TABLE  

  2. CHECK WIRE HARNESS (DRIVER SEAT ECU - POWER SEAT SENSOR AND BODY GROUND) 
    1. Disconnect the D27 and D28 ECU connectors.
    2. Disconnect the P40, P41, P42, P43, P44 and P45 sensor connectors.
    3. Measure the resistance of the wire harness side connectors.

    Standard: 

    TESTER CONNECTION AND SPECIFIED CONDITION

    Tester connection Specified condition
    D27-12 (H+) - P40-1 (UP) Below 1 Ω
    D27-3 (H-) - P40-5 (DOWN) Below 1 Ω
    D28-7(SSRH) - P40-4(O/P) Below 1 Ω
    D28-16 (PVCC) - P40-2 (VCC) Below 1 Ω
    D28-16 (PVCC) - P44-3 (VCC) Below 1 Ω
    D28-13 (SSRR) - P44-1 (O/P) Below 1 Ω
    D28-16 (PVCC) - P43-3 (VCC) Below 1 Ω
    D28-6 (SSRV) - P43-1 (O/P) Below 1 Ω
    D28-16 (PVCC) - P45-3 (VCC) Below 1 Ω
    D28-5 (SSRS) -P45-1 (O/P) Below 1 Ω
    D28-16 (PVCC) - P41-3 (VCC) Below 1 Ω
    D28-15 (SSRC) - P41-1 (O/P) Below 1 Ω
    D28-16 (PVCC) - P42-3 (VCC) Below 1 Ω
    D28-14 (SSFV) - P42-1 (O/P) Below 1 Ω
    D28-1 (SGND) - Body ground Below 1 Ω
    P40-3 (GND) - Body ground Below 1 Ω
    P44-2 (GND) - Body ground Below 1 Ω
    P43-2 (GND) - Body ground Below 1 Ω
    P45-2 (GND) - Body ground Below 1 Ω
    P41-2 (GND) - Body ground Below 1 Ω
    P42-2 (GND) - Body ground Below 1 Ω
    Fig 2: Identifying D27, D28 Driver Seat ECU Connector Terminals And Power Seat Sensor Connector Terminals
    G03000981Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK: GO TO NEXT STEP 

  3. CHECK DRIVER SEAT ECU (SENSOR POWER SOURCE VOLTAGE) 
    1. Turn the ignition switch ON.
    2. Measure the voltage of the ECU connector.

    Standard: 

    TESTER CONNECTION AND SPECIFIED CONDITION

    Tester connection Specified condition
    D28-16 (PVCC) - Body ground 8V
    Fig 3: Identifying D28 Driver Seat ECU Connector Terminals
    G03000982Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE DRIVER SEAT ECU 

    OK: GO TO NEXT STEP 

  4. CHECK POWER SEAT POSITION SENSOR 
    1. Turn the ignition switch ON.
    2. Measure the voltage of the ECU connector.

    Standard: 

    TESTER CONNECTION AND SPECIFIED CONDITION

    Tester Connection Specified Condition When NG, proceed to*
    D28-7 (SSRH) - D28-1 (GND) Varies between 0 to 8 V A
    D28-13 (SSRR) - D28-1 (GND) Varies between 0 to 8 V B
    D28-6 (SSRV) - D28-1 (GND) Varies between 0 to 8 V B
    D28-5 (SSRS) - D28-1 (GND) Varies between 0 to 8 V B
    D28-15 (SSRC) - D28-1 (GND) Varies between 0 to 8 V B
    D28-14 (SSFV) - D28-1 (GND) Varies between 0 to 8 V B

    HINT:

    Check the power seat position sensors that are malfunctioning.

    Run the motors and check that the voltage readings vary within the "specified condition" shown in the chart above.

    *: If the result is not as specified proceed to steps indicated in this column.

    Fig 4: Identifying D28 Driver Seat ECU Connector Terminals
    G03000983Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    A: REPLACE FRONT SEAT HEADREST ADJUSTER 

    B: REPLACE FRONT POWER SEAT ADJUSTER 

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON  PROBLEM SYMPTOMS TABLE