LIGHTING SYSTEM, Diagnostic DTC:B2415

DTC Code DTC Name
B2415 Vehicle Speed Sensor Malfunction

DESCRIPTION

The headlight leveling ECU receives the vehicle speed signal from the combination meter.

Tech Tips


  • A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter. The signal is changed to a pulse signal at the transistor in the combination meter. 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.

DTC No. DTC Detecting Condition Trouble Area
B2415

  • Malfunction in combination meter

  • Open or short in vehicle speed sensor circuit

  • Malfunction in headlight leveling ECU

  • Combination meter

  • Harness or connector

  • Headlight leveling ECU

WIRING DIAGRAM

A003UYAE01

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)


    1. A003T12E52
      Text in Illustration
      *1

      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 E46-36 (+S) and body ground.

      3. Turn the power switch on (IG).

      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 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) in the illustration narrows.


    NG

    GO TO METER / GAUGE SYSTEM Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (HEADLIGHT LEVELING ECU ASSEMBLY - COMBINATION METER ASSEMBLY)


    1. Disconnect the E46 combination meter assembly connector.

    2. Disconnect the A35 headlight leveling ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A35-16 (SPDR) - E46-36 (+S) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE HEADLAMP LEVELING ECU ASSEMBLY Click here