WIPER AND WASHER SYSTEM(w/ Rain Sensor) Speed Signal Circuit

DESCRIPTION

The windshield wiper relay assembly receives a vehicle speed signal from the combination meter assembly to control the auto 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 following diagram will not operate normally.

WIRING DIAGRAM

A01VAAKE01
*1 to Related ECU
*2 Combination Meter Assembly
*3 Windshield Wiper Relay Assembly

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (WINDSHIELD WIPER RELAY ASSEMBLY - COMBINATION METER ASSEMBLY)


    • *1: for Radio Receiver Type

    • *2: for Navigation Receiver Type

    • *3: for Radio and Display Type

    • *4: w/ Automatic Headlight Beam Level Control System

    • *5: w/ Entry and Start System

    • *6: except Manual Transaxle

    • *7: Engine Type Diesel

    • *8: Engine Type Gasoline


    1. Disconnect the G16 combination meter assembly connector.

    2. Disconnect the G85 windshield wiper relay assembly connector.

    3. Disconnect the G16 combination meter assembly connector.

    4. Disconnect the G48 radio receiver assembly connector.*1

    5. Disconnect the G139 navigation ECU sub-assembly connector.*2

    6. Disconnect the G143 radio and display receiver assembly connector.*3

    7. Disconnect the A67 headlight leveling ECU assembly connector.*4

    8. Disconnect the G84 certification ECU (smart key ECU assembly) connector.*5

    9. Disconnect the B79 TCM connector.*6

    10. Disconnect the A61*7 or A62*8 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G85-24 (SPD) - G16-6 (+S) Always Below 1 Ω
      G85-24 (SPD) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)


    1. A01V6TYC03
      *a

      Component with harness connected

      (Combination Meter Assembly)

      Remove the combination meter assembly with the connector(s) still connected.

    2. Connect an oscilloscope to terminal G16-6 (+S) and body ground.

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

      Measurement Condition
      Item Condition
      Terminal No. (Symbol) G16-6 (+S) - Body ground
      Tool Setting 5 V/DIV., 20 ms./DIV.
      Condition Ignition switch ON, wheel being rotated
      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) in the illustration narrows.

      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    GO TO METER / GAUGE SYSTEM Click here