NAVIGATION SYSTEM(for HDD), Diagnostic DTC:B15C2

DTC Code DTC Name
B15C2 Speed Signal Malfunction

DESCRIPTION

The navigation ECU sub-assembly receives a vehicle speed signal from the combination meter assembly and information from the navigation antenna assembly, and then adjusts the vehicle position.

The navigation ECU sub-assembly stores this DTC when the difference between the speed information that the navigation antenna assembly receives and the SPD pulse received from the combination mete rassembly becomes large.

Tip:

  • A voltage of 12 V or 5 V is output from each ECU 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 systems 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.

Detection Item

DTC Detection Condition

Trouble Area

B15C2

Speed Signal Malfunction

A difference between the GPS speed and SPD pulse is detected.

  • Meter/gauge System

  • Harness or connector

  • Navigation ECU sub-assembly

WIRING DIAGRAM

E270426E01

PROCEDURE

  1. CHECK VEHICLE SENSOR (OPERATION CHECK)

    1. E274395

      Enter "GPS & Vehicle Sensor" (Vehicle Sensors)

      Click here

    2. While driving the vehicle, compare the "SPD" indicator to the reading on the speedometer. Check if these readings are equal or almost equal.

    Result

    Proceed to

    The readings are equal or almost equal

    The readings are not equal or almost equal
    The readings are equal or almost equal

    REPLACE NAVIGATION ECU SUB-ASSEMBLY

    Click here

    The readings are not equal or almost equal

  2. CHECK COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)

    1. E190309C01

      *a

      Component with harness connected

      (Combination Meter Assembly)

      Check the output waveform

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

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

      3. Turn the engine switch on (IG).

      4. Turn a wheel slowly.

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

        Item

        Condition

        Measurement terminal

        G16-6 (+S) - Body ground

        Tool setting

        5 V/DIV., 20 ms./DIV.

        Vehicle condition

        Wheel being rotated

        OK

        The waveform is similar to that shown in the illustration.

        Tip:

        When the system is functioning normally, one wheelrevolution generates 4 pulses. As the vehicle speedincreases, the width indicated by A in the illustrationnarrows.

    Result

    Proceed to

    OK

    NG
    NG

    GO TO METER / GAUGE SYSTEM

    Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (NAVIGATION ECU SUB-ASSEMBLY - COMBINATION METER ASSEMBLY)

    1. Disconnect the G139 navigation ECU sub-assemblyconnector.

    2. Disconnect the G16 combination meter assemblyconnector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      G139-17 (SPD) - G16-6 (+S)

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE NAVIGATION ECU SUB-ASSEMBLY

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR