WIPER AND WASHER SYSTEM Speed Signal Circuit

DESCRIPTION

The windshield wiper relay assembly receives a vehicle speed signal from the combination meter to control the automatic windshield wiper system.

A voltage of 12 V or 5 V is output from the combination meter assembly and then input to the skid control ECU.

A voltage of 12 V or 5 V is output from each ECU or relay and then input to the combination meter assembly.

The signal is changed to a pulse signal at the transistor in the combination meter assembly.

Each ECU controls the respective system based on the pulse signal.

If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems in the diagram below will not operate normally.

WIRING DIAGRAM


  1. for 2GR-FXE

    A01NEKPE01

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK COMBINATION METER SYSTEM


    1. The circuit that sends vehicle speed signals to the combination meter system is inspected in the meter section Click here.


    NEXT

  2. CHECK HARNESS AND CONNECTOR (WINDSHIELD WIPER SWITCH ASSEMBLY - COMBINATION METER)


    1. A01NDIWE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Windshield Wiper Switch Assembly)
      *2

      Front view of wire harness connector

      (to Combination Meter Assembly)

      for LHD, RHD Light Control Switch LH Side Type:


      1. Disconnect the F42 windshield wiper switch assembly connector and F15 combination meter connector.

      2. Measure the resistance according to the value(s) in the table below.

        Standard Resistance
        Tester Connection Condition Specified Condition
        F42-6 (SPD) - F15-3 (+S) Always Below 1 Ω
    2. A01NDIWE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Windshield Wiper Switch Assembly)
      *2

      Front view of wire harness connector

      (to Combination Meter Assembly)

      for RHD Light Control Switch RH Side Type:


      1. Disconnect the F81 windshield wiper switch assembly connector and F15 combination meter connector.

      2. Measure the resistance according to the value(s) in the table below.

        Standard Resistance
        Tester Connection Condition Specified Condition
        F81-4 (SPD) - F15-3 (+S) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT COMBINATION METER (SPEED SENSOR SIGNAL)


    1. A01NCPVE10
      Text in Illustration
      *1

      Component with harness connected

      (Combination Meter)

      Check the output waveform.


      1. Remove the combination meter assembly with the connector still connected.

      2. Connect an oscilloscope to terminal F15-3 (+S) and body ground.

      3. Turn the power switch on (IG).

      4. Turn a wheel slowly.

      5. Check the signal waveform according to the condition(s) in the table below.

        Item Condition
        Tool setting 5 V/DIV., 20 ms./DIV.
        Vehicle condition Driving at approx. 20 km/h (12 mph)
        OK
        The waveform is displayed as shown in the illustration.

        Tech Tips

        When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) shown in the illustration narrows.


    NG

    REPLACE COMBINATION METER Click here

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here