NAVIGATION SYSTEM (for HDD), Diagnostic DTC:B15C2

DTC Code DTC Name
B15C2 Speed Signal Malfunction

DESCRIPTION

The navigation computer sub-assembly 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 navigation computer sub-assembly 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

  • Combination meter assembly

  • Navigation computer sub-assembly

  • Wire harness or connector

  • Junction block

WIRING DIAGRAM

A003ZQ1E01

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK VEHICLE SENSOR (OPERATION CHECK)


    1. A003VRX

      Enter the "Vehicle Sensors" screen. Refer to Check GPS & Vehicle Sensor 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 CAN communication. 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

    INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM) Click here

    OK

    REPLACE NAVIGATION COMPUTER SUB-ASSEMBLY Click here

  2. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)


    1. A003VBRE62
      Text in Illustration
      *a

      Component with harness connected

      (Combination Meter Assembly)

      Check the output waveform.


      1. Reconnect the H19 combination meter assembly connector.

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

      3. Connect an oscilloscope to terminal H19-40 (+S) and body ground.

      4. Turn the power switch on (IG).

      5. Turn a wheel slowly.

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

        Item Condition
        Measurement terminal H19-40 (+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.


    NG

    GO TO METER / GAUGE SYSTEM Click here

    OK

  3. CHECK HARNESS AND CONNECTOR


    1. Disconnect the H60 navigation computer sub-assembly connector.

    2. Disconnect the H19 combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H60-18 (SPD) - H19-40 (+S) Always Below 1 Ω

    NG

    CHECK HARNESS AND CONNECTOR Click here

    OK

    REPLACE NAVIGATION COMPUTER SUB-ASSEMBLY Click here

  4. CHECK HARNESS AND CONNECTOR


    1. Disconnect the H60 navigation computer sub-assembly connector.

    2. Disconnect the H117 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H60-18 (SPD) - H117-99 Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    GO TO METER / GAUGE SYSTEM Click here