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.

Tech Tips


  • 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

A01QUAWE01
*1 Combination Meter Assembly
*2 Navigation ECU Sub-assembly

PROCEDURE


  1. CHECK VEHICLE SENSOR (OPERATION CHECK)


    1. A01QQXJ

      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. A01QTIDC01
      *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.

        Tech Tips

        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