2008 Lexus LS 600hLFACTORY OEM SERVICE PROCEDURE

Terminals Of Ecu

  1. CHECK MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY) 
    Fig 1: Identifying A68, L13 And DA Main Body ECU Connectors
    G05780653Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the A68, L13 and DA main body ECU connectors
    2. Measure the voltage and resistance according to the value(s) in the table below
      CONNECTOR TERMINAL REFERENCE

      Terminal No. (Symbols) Wiring Color Terminal Description Condition Specified Condition
      L13-6 (AM1) - Body ground W - Body ground +B power supply Always 11 to 14 V
      L12-1 (AM2) - Body ground W - Body ground +B power supply Always 11 to 14 V
      L13-17 (SSW1) - Body ground W - Body ground Power switch 1 input Power switch pushed Below 1 Ω
      L13-17 (SSW1) - Body ground W - Body ground Power switch 1 input Power switch not pushed 10 kΩ or higher
      L13-16 (SSW2) - Body ground L - Body ground Power switch 2 input Power switch pushed Below 1 Ω
      L13-16 (SSW2) - Body ground L - Body ground Power switch 2 input Power switch not pushed 10 kΩ or higher
      DA-40 (GND1) - Body ground W-B - Body ground Ground Always Below 1 Ω
      DA-23 or DA-52 (LIN1) - Body ground O - Body ground LIN line Always 10 kΩ or higher

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

    3. Reconnect the A68, L13 and DA main body ECU connectors
    4. Measure the voltages according to the value (s) in the table below.
      CONNECTOR TERMINAL REFERENCE

      Terminal No. (Symbols) Wiring Color Terminal Description Condition Specified Condition
      L13-22 (ACCD) - DA-40 (GND1) G - W-B D-ACC relay drive signal Power switch ON (ACC) 11 to 14 V
      L13-22 (ACCD) - DA-40 (GND1) G - W-B D-ACC relay drive signal Power switch OFF Below 1 V
      L12-11 (IG2D) - DA-40 (GND1) P - W-B Ignition relay No 2 (IG2) drive signal Power switch ON (IG) 11 to 14V
      L12-11 (IG2D) - DA-40 (GND1) P - W-B Ignition relay No 2 (1G2) drive signal Power switch ON (ACC) Below 1 V
      L13-19 (SLR+) - DA-40 (GND1) SB - W-B Steering lock power supply Steering lock motor operating Below 1 V
      L13-19 (SLR+) - DA-40 (GND1) SB - W-B Steering lock power supply Steering lock motor not operating 11 to 14 V
      L13-18 (SLP) - DA-40 (GND1) LG - W-B Steering lock actuator position signal Steering lock locked 11 to 14 V
      L13-18 (SLP) - DA-40 (GND1) LG - W-B Steering lock actuator position signal Steering lock released Below 1 V
      L11-9 (SPD) - DA-40 (GND1) V - W-B Speed signal from combination meter Power switch ON (IG), rotate driving wheel slowly Pulse generation (see  1waveform 1)
      L11-8 (RDY) - DA-40 (GND1) W - W-B Power switch ON (READY) signal Power switch ON (READY) Pulse generation (see  2waveform 2)
      A68-2 (P) - DA-40 (GND1) Y - W-B Shift lock signal Shift lever in P Pulse generation (see  3waveform 3)
      A68-2 (P) - DA-40 (GND1) Y - W-B Shift lock signal Shift lever not in P Below 1 V
      A68-4 (STSW) - DA-40 (GND1) B - W-B Hybrid control system activation request signal Brake pedal depressed with shift lever in P, power switch pushed once 11 to 14 V
      L13-15 (INDS) - DA-40 (GND1) B - W-B Vehicle condition signal Brake pedal depressed with shift lever in P, power switch OFF, ON (ACC, IG) 9 to 14 V
      L13-14 (INDW) - DA-40 (GND1) P - W-B Vehicle condition signal Brake pedal released with shift lever in P, power switch OFF, ON (ACC, IG) 9 to 14 V
      L13-25 (SWIL) - DA-40 (GND1) R - W-B Illumination signal Light control switch TAIL or HEAD 11 to 14 V
      DH-15 (STP) - DA-40 (GND1) L - W-B Stop light switch signal Brake pedal depressed 11 to 14 V
      DH-15 (STP) - DA-40 (GND1) L - W-B Stop light switch signal Brake pedal released Below 1 V

      If the result is not as specified, the ECU may have a malfunction.

    5. Using an oscilloscope, check the signal waveform of the ECU
      1. Waveform 1

        Reference 

        WAVEFORM REFERENCE 1

        Terminal No. (Symbols) Tool Setting Condition
        L11-9 (SPD) - DA-40 (GND1) 5V/DIV, 100msec/DIV Driving at approx 20 km/h (12mph)

        HINT:

        As the vehicle speed increases, the wavelength shortens.

        Fig 2: Waveform Graph 1
        G05630958Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. Waveform 2

        Reference 

        WAVEFORM REFERENCE 2

        Terminal No. (Symbols) Tool Setting Condition
        L11-8 (RDY) - DA-40 (GND1) 10V/DIV, 10msec/DIV Power switch ON (IG) or ON (READY)
        Fig 3: Waveform Graph 2
        G05780655Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      3. Waveform 3

        Reference 

        WAVEFORM REFERENCE 3

        Terminal No. (Symbols) Tool Setting Condition
        A68-2 (P) - DA-40 (GND1) 2 V/DIV, 20 msec /DIV Shift lever in P
  2. CHECK CERTIFICATION ECU 
    Fig 4: Waveform Graph 3
    G05630960Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.