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Terminals Of Ecu [12/2019 - 11/2023]

  1. CHECK TIRE PRESSURE WARNING ECU AND RECEIVER 
    1. Disconnect the M51 tire pressure warning ECU and receiver connector and measure the voltage or resistance on the wire harness side.
      GTY880574Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Tire Pressure Warning ECU and Receiver)
      Terminal No. (Symbol) Terminal Description Condition Specified Condition
      M51-1 (IG) - M51-12 (GND) IG power source Ignition switch ON 10 to 16 V
      M51-7 (+B) - M51-12 (GND) Power supply (from auxiliary battery) Always 10 to 16 V
      M51-9 (CANH) - M51-10 (CANL) CAN communication line Ignition switch off 54 to 69 Ω
      M51-12 (GND) - Body ground Ground Always Below 1 Ω
    2. Connect the M51 tire pressure warning ECU and receiver connector.
    3. Measure the voltage according to the value(s) in the table below. If the result is not as specified, the ECU may be malfunctioning.

      HINT: 

      Measure the values on the wire harness side while the connector is connected.

      GTY853815Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Tire Pressure Warning ECU and Receiver)      		 - -
      Terminal No. (Symbol) Terminal Description Condition Specified Condition
      M51-3 (CLSW) - M51-12 (GND) Tire pressure warning reset switch
      • Ignition switch ON
      • Steering pad switch assembly operated, "Set Pressure" selected on the multi-information display and "OK" switch (steering pad switch assembly) pressed and held
      		 Below 1.5 V
      • Ignition switch ON
      • "OK" switch (steering pad switch assembly) off
      		 8 to 15 V
      M51-4 (RDA) - M51-12 (GND) Output signals Ignition switch ON Pulse generation (see waveform 1)
      M51-5 (PRG) - M51-12 (GND) Input signals Ignition switch ON Pulse generation (see waveform 1)
    4. Using an oscilloscope, check waveform 1.
      GTY435468Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Example
      *b GND
      WAVEFORM 1:

      Item Contents
      Terminal M51-4 (RDA) - M51-12 (GND)
      M51-5 (PRG) - M51-12 (GND)
      Tool setting 5 V/DIV, 5 ms./DIV.
      Vehicle condition Ignition switch ON

      HINT: 

      The waveform shown in the illustration is an example. If the tester displays a waveform that alternates between high and low, where high is a voltage that is between the IG power source voltage and a voltage 2.2 V lower than the IG power source voltage, and where low is a voltage of between 0 and 1.2 V, the ECU can be judged normal.

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