TIRE PRESSURE WARNING SYSTEM TERMINALS OF ECU


  1. CHECK TIRE PRESSURE WARNING ECU AND RECEIVER


    1. A01JABXE20
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Tire Pressure Warning ECU and Receiver)

      Disconnect the R33 tire pressure warning ECU and receiver connector and measure the voltage and resistance on the wire harness side.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      R33-1 (IG) - R33-12 (GND) B - W-B IG power source Power switch on (IG) 10 to 16 V
      R33-12 (GND) - Body ground W-B - Body ground Ground Always Below 1 Ω

    2. Connect the R33 tire pressure warning ECU and receiver connector.

    3. Measure the voltage and resistance according to the value(s) in the table below. If the result is not as specified, the ECU may be malfunctioning.

      Tech Tips

      Inspect the connectors from the back side while the connectors are connected.

      A01JAVGE78
      Text in Illustration
      *a

      Component with harness connected

      (Tire Pressure Warning ECU and Receiver)

      		 - -
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      R33-2 (SPD) - R33-12 (GND) V - W-B Vehicle speed signal Vehicle is running Pulse generation (see waveform 1)
      R33-3 (TC) - R33-12 (GND) L - W-B TC terminal Terminal TC is not connected 11 to 14 V
      R33-5 (IND) - R33-12 (GND) G - W-B Tire pressure warning light output signal

      • Power switch on (IG)

      • Tire pressure warning light off

      		 3.2 V or higher

      • Power switch on (IG)

      • Tire pressure warning light on

      		 0.9 to 3.2 V
      R33-7 (CLSW) - R33-12 (GND) Y - W-B Tire pressure warning reset switch signal

      • Power switch on (IG)

      • Tire pressure warning reset switch on

      		 Below 1.5 V

      • Power switch on (IG)

      • Tire pressure warning reset switch off

      		 8 to 15 V
      R33-10 (SIL) - R33-12 (GND) P - W-B Diagnostic tester communication line Power switch on (IG) 11 to 14 V
    4. A01J9UJE40
      Text in Illustration
      *a GND

      Using an oscilloscope, check waveform 1.

      Waveform 1:
      Item Contents
      Terminal R33-2 (SPD) - R33-12 (GND)
      Tool setting 5 V/DIV., 20 ms./DIV.
      Vehicle condition Driving at 20 km/h (12 mph)

      Tech Tips

      The wavelength becomes shorter as the vehicle speed increases.