NAVIGATION SYSTEM, 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 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.

  • Navigation ECU sub-assembly

  • Combination meter assembly

  • Harness or connector

  • No. 2 junction block

WIRING DIAGRAM


  1. for 2GR-FE

    A01CB81E05

  2. for 2AZ-FE

    A01CC9KE03

INSPECTION PROCEDURE

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.

PROCEDURE


  1. CHECK VEHICLE SENSOR (OPERATION CHECK)


    1. A01CDQH

      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 combination meter assembly 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 ECU SUB-ASSEMBLY Click here

  2. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)


    1. A01CFA3E47
      Text in Illustration
      *a

      Component with harness connected

      (Combination Meter Assembly)

      Check the output waveform.


      1. Remove the combination meter assembly with the connector still connected.

      2. Connect an oscilloscope to terminal G19-24 (+S) and body ground.

      3. Turn the engine 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 G19-24 (+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.

    2. Proceed to the next step based on the inspection result.

      Result
      Result Proceed to
      OK (w/ Front Center Speaker) A
      OK (w/o Front Center Speaker) B
      NG C

    B

    INSPECT NAVIGATION ECU SUB-ASSEMBLY (INPUT WAVEFORM) Click here

    C

    GO TO METER / GAUGE SYSTEM Click here

    A

  3. INSPECT NAVIGATION ECU SUB-ASSEMBLY (INPUT WAVEFORM)


    1. A01CB9YE05
      Text in Illustration
      *a

      Component with harness connected

      (Navigation ECU Sub-assembly)

      Check the input waveform.


      1. Remove the navigation ECU sub-assembly with the connector still connected.

      2. Connect an oscilloscope to terminal F23-56 (SPD) and body ground.

      3. Turn the engine 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 F23-56 (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.

        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

    CHECK HARNESS AND CONNECTOR (NAVIGATION ECU SUB-ASSEMBLY - NO. 2 JUNCTION BLOCK) Click here

    OK

    REPLACE NAVIGATION ECU SUB-ASSEMBLY Click here

  4. INSPECT NAVIGATION ECU SUB-ASSEMBLY (INPUT WAVEFORM)


    1. A01CBZ6E09
      Text in Illustration
      *a

      Component with harness connected

      (Navigation ECU Sub-assembly)

      Check the input waveform.


      1. Remove the navigation ECU sub-assembly with the connector still connected.

      2. Connect an oscilloscope to terminal F36-17 (SPD) and body ground.

      3. Turn the engine 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 F36-17 (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.


    NG

    CHECK HARNESS AND CONNECTOR (NAVIGATION ECU SUB-ASSEMBLY - NO. 2 JUNCTION BLOCK) Click here

    OK

    REPLACE NAVIGATION ECU SUB-ASSEMBLY Click here

  5. CHECK HARNESS AND CONNECTOR (NAVIGATION ECU SUB-ASSEMBLY - NO. 2 JUNCTION BLOCK)


    1. Disconnect the F23 navigation ECU sub-assembly connector (w/ Front Center Speaker).

    2. Disconnect the F36 navigation ECU sub-assembly connector (w/o Front Center Speaker).

    3. Disconnect the LH No. 2 junction block connector.

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

      Standard Resistance
      w/ Front Center Speaker
      Tester Connection Condition Specified Condition
      F23-56 (SPD) - LH-4 Always Below 1 Ω
      w/o Front Center Speaker
      Tester Connection Condition Specified Condition
      F36-17 (SPD) - LH-4 Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (NO. 2 JUNCTION BLOCK - COMBINATION METER ASSEMBLY)


    1. Disconnect the LD No. 2 junction block connector.

    2. Disconnect the G19 combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      LD-4 - G19-24 (+S) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 JUNCTION BLOCK - COMBINATION METER ASSEMBLY)

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 JUNCTION BLOCK)