NAVIGATION SYSTEM, Diagnostic DTC:B15C2

DTC Code DTC Name
B15C2 Speed Signal Malfunction

DESCRIPTION

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

The navigation ECU 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.

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 its respective system based on this 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.

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

  • Navigation ECU

  • Radio and display receiver assembly

  • Harness or connector

WIRING DIAGRAM

B00706AE01
*1 Combination Meter Assembly
*2 Navigation ECU

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.

    Click here

  • When replacing the radio and display receiver assembly or navigation ECU, always replace it with a new one. If a radio and display receiver assembly or navigation ECU which was installed to another vehicle is used, the following may occur:


    • A communication malfunction DTC may be stored.

    • The radio and display receiver assembly or navigation ECU may not operate normally.

PROCEDURE


  1. CHECK DTC


    1. Clear the DTCs.


      Body Electrical > Navigation System > Clear DTCs
    2. Recheck for DTCs and check that no DTCs are output.


      Body Electrical > Navigation System > Trouble Codes
      OK
      No DTCs are output.
      Result
      Proceed to
      OK
      NG

    OK
    NG
  2. CHECK VEHICLE SENSOR (OPERATION CHECK)


    1. B006Y5A

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

      Click here

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

      Tech Tips

      The combination meter assembly receives the vehicle speed signal from the skid control ECU via CAN communication. Therefore, perform the following procedure 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 here Click here
      Result
      Proceed to
      OK
      NG

    OK
    NG
  3. CHECK COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)


    1. B006XB9C77
      *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 K21-6 (+S) and body ground.

      3. Turn the ignition switch to ON.

      4. Turn a wheel slowly.

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

        Item Condition
        Measurement terminal K21-6 (+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 wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

      Result
      Proceed to
      OK
      NG

    NG
    OK
  4. CHECK HARNESS AND CONNECTOR (NAVIGATION ECU - COMBINATION METER ASSEMBLY)


    1. Disconnect the K17 navigation ECU connector.

    2. Disconnect the K21 combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K17-9 (SPD) - K21-6 (+S) Always Below 1 Ω
      K17-9 (SPD) or K21-6 (+S) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG
    OK
  5. REPLACE NAVIGATION ECU


    1. Replace the navigation ECU with a new one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT
  6. CHECK DTC


    1. Clear the DTCs.


      Body Electrical > Navigation System > Clear DTCs
    2. Recheck for DTCs and check that no DTCs are output.


      Body Electrical > Navigation System > Trouble Codes
      OK
      No DTCs are output.
      Result
      Proceed to
      OK
      NG

    OK
    NG