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Terminals Of Ecu

  1. CHECK POWER SOURCE CONTROL ECU 
    Fig 1: Identifying K73 ECU Connector Terminals
    GTY103391Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the K73 ECU connector.
    2. Measure the voltage and resistance of the wire harness side connector.
      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      AM1 (K73-33) - Body ground BE - Body ground +B power supply Always 10 to 14 V
      AM2 (K73-12) - Body ground BR - Body ground +B power supply Always 10 to 14 V
      SSW1 (K73-14) - Body ground P - Body ground Engine switch signal Engine switch pushed Below 1 Ω
      SSW1 (K73-14) - Body ground P - Body ground Engine switch signal Engine switch not pushed 10 kΩ or higher
      SSW2 (K73-37) - Body ground B - Body ground Engine switch signal Engine switch pushed Below 1 Ω
      SSW2 (K73-37) - Body ground B - Body ground Engine switch signal Engine switch not pushed 10 kΩ or higher
      GND2 (K73-6) - Body ground W-B - Body ground Ground Always Below 1 Ω
      LIN1 (K73-30) - Body ground W - 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 K73 ECU connector.
    4. Measure the voltage of the connector.
      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      ACCD (K73-11) - GND2 (K73-6) G - W-B ACC signal Engine switch on (ACC) 10 to 14 V
      ACCD (K73-11) - GND2 (K73-6) G - W-B ACC signal Engine switch off Below 1 V
      IG1D (K73-34) - GND2 (K73-6) SB - W-B IG1 signal Engine switch on (IG) 10 to 14 V
      IG1D (K73-34) - GND2 (K73-6) SB - W-B IG1 signal Engine switch on (ACC) Below 1 V
      IG2D (K73-35) - GND2 (K73-6) Y - W-B IG2 signal Engine switch on (IG) 10 to 14 V
      IG2D (K73-35) - GND2 (K73-6) Y - W-B IG2 signal Engine switch on (ACC) Below 1 V
      STP (K73-1) - GND2 (K73-6) V - W-B Stop light signal Brake pedal depressed 10 to 14 V
      STP (K73-1) - GND2 (K73-6) V - W-B Stop light signal Brake pedal released Below 1 V
      SLR+ (K73-32) - GND2 (K73-6) LG - W-B Steering lock motor signal Steering lock motor operating Below 1 V
      SLR+ (K73-32) - GND2 (K73-6) LG - W-B Steering lock motor signal Steering lock motor does not operate 10 to 14 V
      SLP (K73-26) - GND2 (K73-6) V - W-B Steering lock actuator position signal Steering lock is locked 10 to 14 V
      SLP (K73-26) - GND2 (K73-6) V - W-B Steering lock actuator position signal Steering lock is released Below 1 V
      SPD (K73-19) - GND2 (K73-6) L - W-B Vehicle speed signal Engine switch on (IG), rotate rear wheel slowly Pulse generation (see waveform 1)
      TACH (K73-2) - GND2 (K73-6) W - W-B Tachometer signal Engine running Pulse generation (see waveform 2)
      P (K73-5) - GND2 (K73-6) LG - W-B Shift lock signal Shift lever P position 10 to 14 V
      P (K73-5) - GND2 (K73-6) LG - W-B Shift lock signal Shift lever not P position Below 1 V
      CTSW (K73-31) - GND2 (K73-6) R - W-B Starter assist signal Brake pedal depressed, shift lever P position, engine switch is pushed once Below 1 V*1
      STSW (K73-39) - GND2 (K73-6) V - W-B Starter activation request signal Brake pedal depressed, shift lever P position, engine switch is pushed once 10 to 14 V*2
      STR1 (K73-17) - GND2 (K73-6) SB - W-B Park/neutral position switch Shift lever P position Below 1 V
      STR2 (K73-15) - GND2 (K73-6) L - W-B Starter signal Brake pedal depressed, shift lever P position, engine switch is pushed once 10 to 14 V*2
      INDS (K73-4) - GND2 (K73-6) SB - W-B Vehicle condition signal Brake pedal depressed, shift lever P position, engine switch on (ACC, IG) 10 to 14 V
      INDW (K73-13) - GND2 (K73-6) R - W-B Warning signal Brake pedal released, shift lever P position, engine switch on (ACC, IG) 10 to 14 V
      SWIL (K73-36) - GND2 (K73-6) GR - W-B Illumination signal Light control switch TAIL or HEAD 10 to 14 V
      SKSW (K73-28) - GND2 (K73-6) L - W-B Key in vehicle signal Engine switch on (ACC, IG) Below 1 V

      HINT: 

      *1 : Voltage is output only when the engine is cranking.

      *2 : Voltage is output for 0.3 seconds after the engine start.

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

    5. Using an oscilloscope, check the signal waveform of the ECU.
      Fig 2: Identifying Waveform 1
      GTY108735Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      WAVEFORM 1 (REFERENCE):

      Terminal No. K73-19 - Body ground
      Tool Setting 5 V/DIV., 10 msec./DIV.
      Vehicle Condition Driving at approx. 20 km/h (12 mph)

      HINT: 

      As the vehicle speed increases, the wavelength shortens.

      Fig 3: Identifying Waveform 2
      GTY102580Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      WAVEFORM 2 (REFERENCE):

      Terminal No. K73-2 - Body ground
      Tool Setting 5 V/DIV., 10 msec./DIV.
      Vehicle Condition Engine idling

      HINT: 

      As the vehicle speed increases, the wavelength shortens.

  2. CHECK CERTIFICATION ECU 
    Fig 4: Identifying Certification ECU Connector Terminals
    GTY103561Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the U28 and U33 ECU connectors.
    2. Measure the voltage and resistance of the wire harness side connector.
      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      +B1 (U28-1) - Body ground R - Body ground +B power supply Always 10 to 14 V
      IG (U28-18) - Body ground B - Body ground Ignition power supply Engine switch on (IG) 10 to 14 V
      IG (U28-18) - Body ground B - Body ground Ignition power supply Engine switch off Below 1 V
      LIN (U28-10) - Body ground LG - Body ground LIN line Always 10 kΩ or higher
      E (U28-17) - Body ground W-B - Body ground Ground Always Below 1 Ω

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

  3. CHECK ECM 
    Fig 5: Identifying ECM Connector Terminals
    GTY100808Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the A6, E6, E7, E8 and E45 ECM connectors.
    2. Measure the voltage and resistance of the wire harness side connectors.
      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      +B (A6-6) - Body ground B-R - Body ground Power source of ECM Engine switch on (IG) 10 to 14 V
      +B1 (A6-5) - Body ground B-R - Body ground Power source of ECM Engine switch on (IG) 10 to 14 V
      IGSW (A6-17) - Body ground B-W - Body ground Ignition switch signal Engine switch on (IG) 10 to 14 V
      E01 (E6-2) - Body ground W-B - Body ground Ground Always Below 1 Ω
      E02 (E6-1) - Body ground W-B - Body ground Ground Always Below 1 Ω
      E03 (E8-6) - Body ground W-B - Body ground Ground Always Below 1 Ω
      E04 (E45-5) - Body ground W-B - Body ground Ground Always Below 1 Ω
      E05 (E45-3) - Body ground W-B - Body ground Ground Always Below 1 Ω
      E1 (E7-7) - Body ground BR - Body ground Ground Always Below 1 Ω
      EC (A6-2) - Body ground W-B - Body ground Ground Always Below 1 Ω
      ME01 (E8-4) - Body ground W-B - Body ground Ground Always Below 1 Ω

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

    3. Reconnect the A6, E6, E7, E8 and E45 ECM connectors.
    4. Measure the voltage of the connectors.
      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      STA (A6-12) - E1 (E7-7) R - BR Starter relay operation signal Cranking 10 to 14 V
      ACCR (A6-11) - E1 (E7-7) W-L - BR ACC relay cut signal (output) Engine switch on (IG) 10 to 14 V
      TACH (A7-16) - E1 (E7-7) W-L - BR Engine revolution signal (output) Idling Pulse generation (see waveform 1)
      STP (A7-4) - E1 (E7-7) R-B - BR Stop light switch signal (input) Brake pedal depressed 7.5 to 14 V
      STP (A7-4) - E1 (E7-7) R-B - BR Stop light switch signal (input) Brake pedal released Below 1.5 V
      STAR (E7-4) - E1 (E7-7) L-Y - BR PNP switch signal (input) Engine switch on (IG), shift position P or N 10 to 14 V
      KSW (A6-31) - E1 (E7-7) L - BR Engine switch signal (input) Engine switch off 4 to 6 V
      KSW (A6-31) - E1 (E7-7) L - BR Engine switch signal (input) Moment engine switch is pushed once 10 to 14 V
      KSW (A6-31) - E1 (E7-7) L - BR Engine switch signal (input) Engine switch on (ACC) Below 1.5 V

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

    5. Using an oscilloscope, check the signal waveform of the ECM.
      Fig 6: Identifying Waveform 2
      GTY102580Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      WAVEFORM 1 (REFERENCE):

      Terminal No. A7-16 - Body ground
      Tool Setting 5 V/DIV., 10 msec./DIV.
      Vehicle Condition Engine idling

      HINT: 

      As the vehicle speed increases, the wavelength shortens.

  4. CHECK STEERING LOCK ECU 
    Fig 7: Identifying Steering Lock ECU Connector Terminals
    GTY105899Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the K28 ECU connector.
    2. Measure the voltage and resistance of the wire harness side connector.
      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      B (K28-7) - Body ground L - Body ground +B power supply Always Always
      IG2 (K28-6) - Body ground B - Body ground Ignition power supply Engine switch on (IG) Always
      IG2 (K28-6) - Body ground B - Body ground Ignition power supply Engine switch off Below 1 V
      GND (K28-1) - Body ground W-B - Body ground Ground Always Below 1 Ω
      SGND (K28-2) - Body ground W-B - Body ground Ground Always Below 1 Ω
      • If the result is not as specified, there may be a malfunction on the wire harness side.
    3. Reconnect the K28 ECU connector.
    4. Measure the voltage of the connector.
      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      SLP1 (K28-4) - GND (K28-1) V - W-B Steering lock actuator position signal Steering is locked 10 to 14 V
      SLP1 (K28-4) - GND (K28-1) V - W-B Steering lock actuator position signal Steering is released Below 1 V
      • If the result is not as specified, the ECU may have a malfunction.
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