NAVIGATION SYSTEM (for HDD), Diagnostic DTC:B15C2

DTC Code DTC Name
B15C2 Speed Signal Malfunction

DESCRIPTION

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

The display and navigation module display stores this DTC when the difference between the speed information that the navigation antenna 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 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. DTC Detection Condition Trouble Area
B15C2 A difference between the GPS speed and SPD pulse is detected

  • Wire harness or connector

  • Combination meter assembly

  • Display and navigation module display

WIRING DIAGRAM

A0160GVE17

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK VEHICLE SENSOR (OPERATION CHECK)


    1. A0160O8

      Enter the "Vehicle Sensors" 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 meter ECU receives the vehicle speed signal from the skid control ECU via the direct line. Therefore, perform the following inspection referring to values on the Data List of the skid control ECU because it is the source of the vehicle speed signal.

      OK
      Vehicle speed displayed on the "Vehicle Sensors" screen is almost the same as the actual vehicle speed measured using the intelligent tester (See page Click here).

    NG

    CHECK HARNESS AND CONNECTOR Click here

    OK

    REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY Click here

  2. CHECK HARNESS AND CONNECTOR


    1. Disconnect the J122 display and navigation module display connector.

    2. Disconnect the J34 combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J122-18 (SPD) - J34-5 (+S) Always Below 1 Ω
      J122-18 (SPD) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)


    1. Reconnect the J34 combination meter assembly connector.

    2. Disconnect the J122 display and navigation module display connector.

    3. A01605OE44

      Check the output waveform.


      1. Connect an oscilloscope to terminal J122-18 (SPD) and body ground.

      2. Turn the engine switch on (IG).

      3. Turn a wheel slowly.

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

        A0162TDE07
        Item Condition
        Measurement terminal J122-18 (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.

        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.

      Text in Illustration
      *1

      Front view of wire harness connector

      (to Display and Navigation Module Display)

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

    OK

    REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY Click here