WIPER AND WASHER SYSTEM Speed Signal Circuit

DTC Code DTC Name
Speed Signal Circuit

DESCRIPTION

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

WIRING DIAGRAM

  1. for 1NR-FE

    E342268E02

  2. for 1ZR-FAE

    E316165E02

  3. for 1ND-TV

    E380066E01

  4. for 1ZR-FE, 2ZR-FE

    E342268E03

  5. for 8NR-FTS

    E321603E01

  6. for 1WW

    E267215E02

PROCEDURE

  1. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)

    1. E262405C24

      *a

      Component with harness connected

      (Combination Meter Assembly)

      Check the output waveform.

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

      2. Connect an oscilloscope to terminal E46-6 (+S) and body ground.

      3. Turn the ignition switch to ON.

      4. 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

        Wheel being rotated

        OK

        The waveform is displayed as shown in the illustration.

        Tip:

        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

    Result

    OK

    NG
    NG

    GO TO METER / GAUGE SYSTEM

    Click hereClick here

    OK

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

    1. Disconnect the E95 windshield wiper relay assembly connector.

    2. Disconnect the E46 combination meter assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      E95-24 (SPD) - E46-6 (+S)

      Always

      Below 1 Ω

    Result

    Result

    OK

    NG
    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR