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Terminals Of Ecu: Notes

  1. CHECK COMBINATION METER ASSY 
    Fig 1: Checking Combination Meter Assy
    G02956762Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the C8 meter connector.
    2. Measure the voltage and resistance of the wire harness side connector.

      Standard: 

      COMBINATION METER ASSY (DISCONNECTED)

      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      IG+ (C8-1) - Body ground R-Y - Body ground Ignition switch power supply Ignition switch OFF Below 1 V
      IG+ (C8-1) - Body ground R-Y - Body ground Ignition switch power supply Ignition switch ON 10 to 14 V
      ES (C8-11) - Body ground BR - Body ground Ground Always Below 1 ohms
      B (C8-12) - Body ground B - Body ground Battery Always 10 to 14 V

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

    3. Reconnect the C8 meter connector.
    4. Measure the voltage and resistance of the connectors.
      COMBINATION METER ASSY (RECONNECTED)

      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      MPX+ (C8-2) - ES (C8-11) Y - BR Multiplex network communication signal - -
      MPX+ (C8-3) - ES (C8-11) L-O - BR Multiplex network communication signal - -
      S (C8-4) - ES (C8-11) B-Y - BR Tachometer signal (Input) Engine running Pulse generation (see Fig 2 )
      CHK (C8-5) - Body ground R-B - Body ground MIL warning signal Ignition switch ON, MIL OFF 10 to 14 V
      CHK (C8-5) - Body ground R-B - Body ground MIL warning signal Ignition switch ON, MIL ON Below 1 V
      A/B (C8-7) - ES (C8-11) R - BR ODO/TRIP signal Ignition switch ON, ODO/TRIP not pressed Below 1 V
      A/B (C8-7) - ES (C8-11) R - BR ODO/TRIP signal Ignition switch ON, ODO/TRIP pressed 4.5 to 5.5 V
      RSET (C8-8) - ES (C8-11) P - BR RESET signal Ignition switch ON, RESET not pressed Below 1 V
      RSET (C8-8) - ES (C8-11) P - BR RESET signal Ignition switch ON, RESET pressed 4.5 to 5.5 V
      PBLT (C8-9) - Body ground L-R - Body ground Passenger side seat belt warning signal Ignition switch ON, passenger side seat belt unfastened (ON) 10 to 14 V
      PBLT (C8-9) - Body ground L-R - Body ground Passenger side seat belt warning signal Ignition switch ON, passenger side seat belt fastened (OFF) Below 1 V
      TURN L (C8-13) - Body ground G-B - Body ground Turn signal indicator LH signal Ignition switch ON, turn signal indicator lamp LH OFF 10 to 14 V
      TURN L (C8-13) - Body ground G-B - Body ground Turn signal indicator LH signal Ignition switch ON, turn signal indicator lamp LH ON Below 1 V
      TURN R (C8-14) - Body ground G-Y - Body ground Turn signal indicator RH signal Ignition switch ON, turn signal indicator lamp RH OFF 10 to 14 V
      TURN R (C8-14) - Body ground G-Y - Body ground Turn signal indicator RH signal Ignition switch ON, turn signal indicator lamp RH ON Below 1 V
      ILL- (C8-16) - Body ground W-L - Body ground Rheostat signal Ignition switch ON Pulse generation
      S1 (C8-18) - Body ground V - Body ground Vehicle speed signal (output) Ignition switch ON, slowly turn rear wheel Pulse generation (see Fig 3 )
      +S (C8-19) - Body ground W-R - Body ground Vehicle speed signal (output) Ignition switch ON, slowly turn rear wheel Pulse generation (see Fig 3 )
      FR (C8-20) - FE (C8-21) Y-R - Y-G Fuel sender gauge signal Ignition switch ON, fuel level F 0.5 V
      +F (C9-1) - Body ground (3) Y - Body ground Magnetic field sensor drive signal Ignition switch ON Pulse generation
      E (C9-2) - Body ground (3) BR - Body ground Magnetic field sensor earth Always Below 1 ohms
      YSSR (C9-3) - Body ground (3) R - Body ground Compass signal of North-South direction - (1)
      COMN (C9-4) - Body ground (3) L - Body ground Magnetic field sensor power supply Ignition switch ON Approximately 2.5 V (2)
      XSSR (C9-5) - Body ground (3) W - Body ground Compass signal of East-West direction - (1)
      CMP.1 (C9-7) - Body ground (3) Shielded - Body ground Wire harness shield between combination meter and magnetic field sensor Always Below 1 ohms
      (1) The voltage changes depending on vehicle direction, location, etc.

      (2) When the meter CPU wakes up by the ignition switch power supply, approximately 2.5 V will be output.

      (3) w/o LEXUS navigation system

      If the result is not as specified, the combination meter may be malfunctioning.

      Waveform 1 (Reference): 

      WAVEFORM 1 (REFERENCE)

      Symbols (Terminal No.) S (C8-4) - (C8-11)
      Tester Range 5 V/DIV., 10 msec./DIV.
      Vehicle Condition Driving at approx. 20 km/h (12 mph)

      HINT:

      As engine speed increases, the wavelength shortens.

      Fig 2: Identifying Waveform 1 (Reference)
      G02956763Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Waveform 2 (Reference): 

      WAVEFORM 2 (REFERENCE)

      Symbols (Terminal No.) S1 (C8-18) - Body ground
      Tester Range 5 V/DIV., 20 msec./DIV.
      Vehicle Condition Engine idling

      HINT:

      As engine speed increases, the wavelength shortens.

      Fig 3: Identifying Waveform 2 (Reference)
      G02956764Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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