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NAVIGATION SYSTEM, Diagnostic DTC:B15C2

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DTC Code DTC Name
B15C2 Speed Signal Malfunction
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DESCRIPTION

The radio receiver 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 radio receiver 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 meter assembly 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 its respective systems based on this pulse signal.

  • If a short occurs in any of the ECUs or a wire harness connected to an ECU, all systems in the following diagram will not operate normally.

DTC No. Detection Item DTC Detection Condition Trouble Area
B15C2 Speed Signal Malfunction Difference between the GPS speed and SPD pulse is detected
  • Radio receiver assembly

  • Combination meter assembly

  • Harness or connector

  • Junction connector

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WIRING DIAGRAM

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CAUTION / NOTICE / HINT

Note:

Depending on the parts that are replaced during vehicle inspection or maintenance, performing initialization, registration or calibration may be needed. Refer to Precaution for Navigation System.

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PROCEDURE


  1. Click here

    CHECK VEHICLE SENSOR (OPERATION CHECK)


    1. A00084Q

      Enter the "System Sensors Check" screen. Refer to Check GPS & Vehicle Sensors in Operation Check.

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    2. While driving the vehicle, compare the value of "Speed" to the reading on the speedometer. Check if these readings are almost equal.

      Tip:

      The combination meter assembly receives the vehicle speed signal from the skid control ECU via CAN communication. Therefore, perform the following inspection referring to values in the Data List of the skid control ECU because it is the source of the vehicle speed signal.

      OK
      Vehicle speed displayed on the "System Sensors Check" screen is almost the same as the actual vehicle speed measured using the GTS.
      Click hereClick here
      Result
      Proceed to
      OK
      NG

  2. Click here

    INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)


    1. A0008ZQC01
      *a

      Component with harness connected

      (Combination Meter Assembly)

      Check the output waveform.


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

      2. Connect an oscilloscope to terminal H14-19 (+S) and body ground.

      3. Turn the power switch on (IG).

      4. Turn a wheel slowly.

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

        Item Condition
        Measurement terminal H14-19 (+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 wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

      Result
      Proceed to
      OK
      NG

  3. Click here

    INSPECT RADIO RECEIVER ASSEMBLY (INPUT WAVEFORM)


    1. A0004SPC01
      *a

      Component with harness connected

      (Radio Receiver Assembly)

      Check the input waveform.


      1. Remove the radio receiver assembly with the connector(s) still connected.

      2. Connect an oscilloscope to terminal H97-56 (SPD) and body ground.

      3. Turn the power switch on (IG).

      4. Turn a wheel slowly.

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

        Item Condition
        Measurement terminal H97-56 (SPD) - 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 wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

      Result
      Proceed to
      OK
      NG

  4. Click here

    CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - JUNCTION CONNECTOR)


    1. Disconnect the H14 combination meter assembly connector.

    2. Disconnect the H115 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H14-19 (+S) - H115-21 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. Click here

    CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - JUNCTION CONNECTOR)


    1. Disconnect the H97 radio receiver assembly connector.

    2. Disconnect the H114 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H97-56 (SPD) - H114-15 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    • OK

      REPAIR OR REPLACE JUNCTION CONNECTOR

    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR