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Power Seat Control System - Diagnostics: Pre-Check

  1. POWER SEAT CONTROL SYSTEM FOR DRIVER'S SEAT 
    1. Description

      This system sends a signal from the driver's seat control switch to the power seat control ECU when manual operation for seat position is performed.

      HINT:

      Indicator, etc. that indicates such as operating conditions does not exist at the infrared signal transmission and reception part.

    2. Fail-safe function

      When infrared data communication is blocked by an object placed under the seat, etc. or the driver's seat control switch has an abnormality, the system enters fail-safe functions and only slide operation (back and forward) can be operated.

    3. Clean the infrared light reception and emission part Extreme dirt on the power seat control ECU and on the reception and emission part of the infrared signal of the driver's seat control switch does not allow to send and to receive the signal. In this case, wipe the lens with a soft cloth.
    Fig 1: Identifying Power Seat Control System For Driver'S Seat
    G02987516Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. DIAGNOSIS SYSTEM 
    1. Description

      ECU data of this system can be read from DLC3 of the vehicle.

      Therefore when there seems to be a trouble on this system, use hand-held tester to check and troubleshoot it.

      Fig 2: Connecting Hand-Held Tester
      G02987517Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the DLC3.

      The vehicle's ECM uses ISO 9141-2 for communication. The terminal arrangement of DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

    Fig 3: Identifying Connector Terminals DLC3
    G02987518Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    TERMINAL NO AND CONDITION

    Terminal No. Connection/Specified Condition Condition
    4 Chassis Ground --> Body Ground/1 or less Always
    13 TC --> Body Ground/9 - 14 V Always

    HINT:

    If the display shows "UNABLE TO CONNECT TO VEHICLE" when the cable of the hand-held tester is connected to DLC3, the ignition switch is turned ON and the hand-held tester is operated, there is a problem either on the vehicle side or the tool side.

    • If communication is normal when the tool is connected to another vehicle, inspect DLC3 on the original vehicle.
    • If communication does not function when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.
  3. DATA LIST 

    HINT:

    By the DATA LIST displayed on the Hand-held tester, you can read the value of the switch, sensor, actuator and so on without removing any parts. Reading the DATA LIST as a first step of troubleshooting is one of the method to shorten the labor time.

    1. Turn the ignition switch OFF.
    2. Connect the hand-held tester to DLC3.
    3. Turn the ignition switch ON.
    4. According to the display on tester, read the "DATA LIST".

    POWER SEAT CONTROL ECU: 

    POWER SEAT CONTROL ECU DESCRIPTION

    Item Condition Normal Condition Diagnostic Note
    RECLIN SW REAR Reclining rear switch free -->ON OFF --> ON -
    RECLIN SW FRONT Reclining front switch free --> ON OFF --> ON -
    F VTCL SW DOWN Front vertical switch free --> DOWN OFF --> ON -
    FVTCL SW UP vFront vertical switch free --> UP OFF --> ON -
    R VTCL SW DOWN Rear vertical switch free --> DOWN OFF --> ON -
    R VTCL SW UP Rear vertical switch free --> UP OFF --> ON -
    SLIDE SW REAR Slide switch free --> REAR OFF --> ON -
    SLIDE SW FRONT Slide switch free --> FRONT OFF --> ON -
    SLIDE SW RR (W/H) Slide switch free --> REAR OFF --> ON -
    SLIDE SW FR (W/H) Slide switch free --> FRONT OFF --> ON -
    POWER VOLTAGE Ignition switch ON Battery positive voltage -
    MOTOR STATUS - STANDBY/MOVING/LOCK -
    IG SW Ignition switch ON OFF --> ON -
    KEY UNLOCK SW Ignition switch ON OFF --> ON -
    D-DOOR WARN SW Door (door courtesy switch) CLOSE --> OPEN OFF --> ON -
    PNP SW PNP switch except P --> P OFF --> ON -
    PKBS SW Parking brake switch OFF --> ON OFF --> ON -
    M2 SW Memory switch (M2) free --> ON OFF --> ON -
    M1 SW Memory switch (M1) free --> ON OFF --> ON -
    SET SW Memory switch (SET) free --> ON OFF --> ON -
    SLIDE POS - -4096 - 4096 -
    RECLIN POS - -4096 - 4096 -
    F VTCL POS - -4096 - 4096 -
    R VTCL POS - -4096 - 4096 -
    MEM M1 SW Store (M1) None --> Exist NOT MEM --> MEM -
    MEM M2 SW Store (M2) None --> Exist NOT MEM --> MEM -
    SEAT MEM M1 Store seat position (M2) None --> Exist NOT MEM --> MEM -
    SEAT MEM M2 Store seat position (M2) None --> Exist NOT MEM --> MEM -
    D-MIRR MEM M1 Store driver side mirror position (M1) None --> Exist NOT MEM --> MEM -
    D-MIRR MEM M2 Store driver side mirror position (M2) None --> Exist NOT MEM --> MEM -
    P-MIRR MEM M1 Store front passenger side mirror position (M1) None --> Exist NOT MEM --> MEM -
    P-MIRR MEM M2 Store front passenger side mirror position (M2) None --> Exist NOT MEM --> MEM -
    SLIDE MEM POS 1 Stored slide position (M1) -4096 - 4096 -
    RECLN MEM POS 1 Stored reclining position (M1) -4096 - 4096 -
    F VTCL MEM POS1 Stored front vertical position (M1) -4096 - 4096 -
    R VTCL MEM POS1 Stored rear vertical position (M1) -4096 - 4096 -
    SLIDE MEM POS 2 Stored slide position (M2) -4096 - 4096 -
    RECLN MEM POS 2 Stored reclining position (M2) -4096 - 4096 -
    F VTCL MEM POS2 Stored front vertical position (M2) -4096 - 4096 -
    R VTCL MEM POS2 Stored rear vertical position (M2) -4096 - 4096 -
    D-MIR MEM POS 1 Stored driver side outer mirror position (M1) 0 - 65535 -
    P-MIR MEM POS 1 Stored front passenger side outer mirror position (M1) 0 - 65535 -
    D-MIR MEM POS 2 Stored driver side outer mirror position (M2) 0 - 65535 -
    P-MIR MEM POS 2 Stored front passenger side outer mirror position (M2) 0 - 65535 -

    MIRROR CONTROL ECU: 

    MIRROR CONTROL ECU DESCRIPTION

    Item Condition Normal Condition Diagnostic Note
    MIRR POS SW R Mirror switch position RIGHT OFF --> ON OFF --> ON -
    MIRR POS SW L Mirror switch position LEFT OFF --> ON OFF --> ON -
    MIRR POS SW DWN Mirror switch DOWN OFF --> ON OFF --> ON -
    MIRR POS SW UP Mirror switch UP OFF --> ON OFF --> ON -
    MIRR SEL SW Mirror switch select direction MID (P)/D (P) -
    REV POS SW Shift lever position except R --> R OFF --> ON -
    ACC (MPX) Ignition switch ON (ACC) ON -
    IG (MPX) Ignition switch ON ON BEAN signal
    D MIR POS SEN V Driver side outer mirror VERTICAL position (LSB 0.01953 V) 0 - 5 -
    D MIR POS SEN H Driver side outer mirror HORIZON position (LSB 0.01953 V) 0 - 5 -
    P MIR POS SEN V Passenger side outer mirror VERTICAL position (LSB 0.01953 V) 0 - 5 -
    P MIR POS SEN H Passenger side outer mirror HORIZON position (LSB 0.01953 V) 0 - 5 -
  4. ACTIVE TEST 

    HINT:

    Performing ACTIVE TEST using the Hand-held tester allows the relay, and so on to operate without removing any parts. Performing ACTIVE TEST as a first step of troubleshooting is one of the method to shorten the labor time.

    DATA LIST can be displayed during ACTIVE TEST.

    1. Turn the ignition switch OFF.
    2. Connect the Hand-held tester to DLC3.
    3. Turn the ignition switch ON.
    4. According to the display on tester, perform the "ACTIVE TEST".

    POWER SEAT CONTROL ECU: 

    POWER SEAT CONTROL ECU DESCRIPTION

    Tester Display Item (Condition) Parameter Parameter (Min. - Max.) Step (Unit) Diagnostic Note
    RECLINING Seat reclining operation FRONT/REAR - - Confirm that the vehicle is parked./Caution: This test causes vehicle parts to move. Watch your hands and feet.
    F VERTICAL Front vertical operation UP/DOWN - - Confirm that the vehicle is parked./Caution: This test causes vehicle parts to move. Please watch your hands and feet.
    R VERTICAL Rear vertical operation UP/DOWN - - Confirm that the vehicle is parked./Caution: This test causes vehicle parts to move. Please watch your hands and feet.
    SLIDE Seat slide operation FRONT/REAR - - Confirm that the vehicle is parked./Caution: This test causes vehicle parts to move. Please watch your hands and feet.

    MIRROR CONTROL ECU: 

    MIRROR CONTROL ECU DESCRIPTION

    Tester Display Item (Condition) Parameter Parameter (Min. - Max.) Step (Unit) Diagnostic Note
    D MIRR UP/DN Driver side outer mirror UP or DOWN operation UP/DOWN - - -
    D MIRR R/L Driver side outer mirror RIGHT or LEFT operation LEFT/RIGHT - - -
    P MIRR UP/DN Passenger side outer mirror UP or DOWN operation UP/DOWN - - -
    P MIRR R/L Driver side outer mirror RIGHT or LEFT operation LEFT/RIGHT - - -
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