LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2009 >> Sienna LE, AWD >> Repair and Diagnosis >> Body & Frame >> Seats >> Front Power Seat Control System >> Terminals Of Ecu
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Terminals Of Ecu

  1. POSITION CONTROL ECU AND SWITCH ASSEMBLY (POWER SEAT CONTROL SWITCH AND ECU) 
    1. Disconnect the P58 and P59 connectors.
      Fig 1: Identifying P58 And P59 Connectors Terminals
      G05141796Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the voltage of each terminal of the wire harness side connectors.
      TERMINALS REFERENCE

      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      IG (P59-4) - GND (P58-1) Y - W-B Ignition switch Ignition switch off → ignition switch on Below 1 V → 10 to 14 V
      SYSB (P59-8) - GND (P58-1) W-L - W-B Power source Always 10 to 14 V
      +B (P58-5) - GND (P58-1) V - W-B Battery Always 10 to 14 V

      If the result is not as specified, there may be a malfunction in the wire harness side.

    3. Check the resistance of each terminal of the wire harness side connectors.
      TERMINALS REFERENCE

      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      GND (P58-1)- Body ground W-B - Body ground Ground Always Below 1 Ω

      If the result is not as specified, there may be a malfunction in the wire harness side.

    4. Reconnect the P58 and P59 connectors.
    5. Check the voltage of each terminal of the connectors.
      TERMINALS REFERENCE

      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      MPX1 (P59-1) - GND (P58-1) R-L - W-B Multiplex communication signal circuit Ignition switch on Pulse generation
      SLD+ (P58-2) - GND (P58-1) L-W-B Sliding motor signal (Forward) Seat moving forward using sliding switch → Other conditions 10 to 14V → Below 1 V
      SLD- (P58-3) - GND (P58-D L-B - W-B Sliding motor signal (Rearward) Seat moving rearward using sliding switch → Other conditions 10 to 14 V → Below 1V
      FRV- (P58-4) - GND (P58-1) R - W-B Front vertical motor signal (Downward) Seat cushion front portion lowering using front vertical switch → Other conditions 10 to 14V → Below 1 V
      FRV+ (P58-6) - GND (P58-1) L-Y - W-B Front vertical motor signal (Upward) Seat cushion front portion rising using front vertical switch → Other conditions 10 to 14 V → Below 1 V
      LFT+ (P58-7) - GND (P58-D Y-G - W-B Lifter motor signal (Upward) Seat rising using lifter switch → Other conditions 10 to 14 V → Below 1 V
      RCL+ (P58-8) - GND (P58-1) R-G - W-B Reclining motor signal (Forward) Seatback moving forward using reclining switch → Other conditions 10 to 14 V → Below 1 V
      LFT- (P58-9) - GND (P58-D Y - W-B Lifter motor signal (Downward) Seat lowering using lifter switch → Other conditions 10 to 14 V → Below 1 V
      RCL- (P58-10) - GND (P58-1) R-B - W-B Reclining motor signal (Rearward) Seatback moving rearward using reclining switch → Other conditions 10 to 14 V → Below 1 V

      If the result is not as specified, the position control ECU and switch assembly may be malfunctioning.

  2. OUTER MIRROR CONTROL ECU LH 
    1. Disconnect the outer mirror control ECU LH connector.
      Fig 2: Identifying Outer Mirror Control ECU LH Connector Terminals
      G05141797Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the voltage of each terminal of the wire harness side connectors.
      TERMINALS REFERENCE

      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      CPUB (O9-4) - GND (O9-1) W-L - W-B Power source Always 10 to 14 V
      BDR (O9-6) - GND (O9-1) R-L - W-B Power window motor power source Always 10 to 14 V
      SIG (O9-3) - GND (O9-1) B-R - W-B Ignition switch signal Ignition switch off → ignition switch on Below 1 V → 10 to 14 V

      If the result is not as specified, there may be a malfunction in the wire harness side.

    3. Check the resistance of each terminal of the wire harness side connector.
      TERMINALS REFERENCE

      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      GND (O9-1)-Body ground W-B - Body ground Ground Always Below 1 Ω

      If the result is not as specified, there may be a malfunction in the wire harness side.

    4. Reconnect the outer mirror control ECU LH connector.
    5. Check the voltage of each terminal of the connectors.
      TERMINALS REFERENCE

      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      MM (O9-25) - GND (O9-1) W-R - W-B SET switch signal SET switch is not pushed → pushed 10 to 14 V → Below 1 V
      M1 (O9-22)-GND (O9-1) B-W - W-B SW1 switch signal SW1 switch is not pushed → pushed 10 to 14 V → Below 1 V
      M2 (O9-23)-GND (O9-1) V-W-B SW2 switch signal SW2 switch is not pushed → pushed 10 to 14 V → Below 1 V

      If the result is not as specified, the outer mirror control ECU LH may be malfunctioning.

scientia non olet · About LEMON Manuals