Audio And Visual System (For Sedan) Vehicle Speed Signal Circuit Between Radio Receiver And Combination Meter

AudioVisualTelematics. Yaris. Ncp93, 131
Audio Video. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK OPERATION OF SPEEDOMETER

CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - RADIO RECEIVER ASSEMBLY)

CHECK COMBINATION METER ASSEMBLY (VOLTAGE)

INSPECT COMBINATION METER ASSEMBLY (SPD SIGNAL OUTPUT WAVEFORM)

INSPECT COMBINATION METER ASSEMBLY (SPD SIGNAL INPUT WAVEFORM)

CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - SPEEDOMETER SENSOR)

AUDIO AND VISUAL SYSTEM (for Sedan) - Vehicle Speed Signal Circuit between Radio Receiver and Combination Meter


DESCRIPTION

The circuit is necessary for the ASL (Automatic Sound Levelizer) built into the radio receiver assembly.
Speed signals are received from the combination meter assembly and used for the ASL.
The ASL function automatically adjusts the sound volume in order to enable clear audio quality even when vehicle noise increases (as vehicle noise increases, the volume is turned up etc.).
HINT:
  1. 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 system based on the pulse signal.
  2. 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.

WIRING DIAGRAM


Yaris. Ncp93, 131.Audio Video.Audio And Visual System (For Sedan).Audio And Visual System (For Sedan) Vehicle Speed Signal Circuit Between Radio Receiver And Combination Meter


INSPECTION PROCEDURE

1.CHECK OPERATION OF SPEEDOMETER

  1. Drive the vehicle and check whether the operation of the speedometer in the combination meter is normal.

    OK:
    The operation of the speedometer is normal.
    HINT:
    The vehicle speed sensor is operating normally if the speedometer reading is normal.


NG
GO TO SPEEDOMETER MALFUNCTION (YARIS_NCP93 RM000001DAL00MX.html)
OK


2.CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - RADIO RECEIVER ASSEMBLY)

  1. Disconnect the D1 combination meter assembly connector.

  1. Disconnect the D74 radio receiver assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    D1-16 - D74-3 (SPD)
    		Always
    		Below 1 Ω
    D1-16 - Body ground
    		Always
    		10 kΩ or higher
    HINT:
    If the wire has a short, check the speed signal circuit in other systems related to the vehicle speed signal.


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (OTHER SYSTEMS RELATED TO SPEED SIGNAL)
OK


3.CHECK COMBINATION METER ASSEMBLY (VOLTAGE)


    Yaris. Ncp93, 131.Audio Video.Audio And Visual System (For Sedan).Audio And Visual System (For Sedan) Vehicle Speed Signal Circuit Between Radio Receiver And Combination Meter

  1. Disconnect the D1 combination meter assembly connector.

    HINT:
    Disconnect the ECU connectors on the other systems related to the speed signal (but the radio receiver assembly connector must be connected).

  1. Turn the ignition switch to ON.

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D1-16 - Body ground
    		Ignition switch ON
    		4.5 to 5.5 V
    Text in Illustration
    *a
    		Front view of wire harness connector
    (to Combination Meter Assembly)


NG
REPLACE RADIO RECEIVER ASSEMBLY (YARIS_NCP93 RM000002AUJ00IX.html)
OK


4.INSPECT COMBINATION METER ASSEMBLY (SPD SIGNAL OUTPUT WAVEFORM)


    Yaris. Ncp93, 131.Audio Video.Audio And Visual System (For Sedan).Audio And Visual System (For Sedan) Vehicle Speed Signal Circuit Between Radio Receiver And Combination Meter

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

  1. Move the shift lever to the neutral position.

  1. Jack up the vehicle.

  1. Turn the ignition switch to ON.

  1. Check the voltage between the terminal of the combination meter and the body ground while the wheel is turned slowly.

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D1-16 - Body ground
    		Ignition switch ON
    (Turn wheel slowly)
    		Voltage generated intermittently
    Text in Illustration
    *a
    		Component with wire harness connected
    (Combination Meter Assembly)
    *b
    		Turn Wheel
    HINT:
    The output voltage should fluctuate up and down, similarly to the diagram, when the wheel is turned slowly.


NG
Go to step 5
OK

REPLACE RADIO RECEIVER ASSEMBLY (YARIS_NCP93 RM000002AUJ00IX.html)

5.INSPECT COMBINATION METER ASSEMBLY (SPD SIGNAL INPUT WAVEFORM)


    Yaris. Ncp93, 131.Audio Video.Audio And Visual System (For Sedan).Audio And Visual System (For Sedan) Vehicle Speed Signal Circuit Between Radio Receiver And Combination Meter

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

  1. Move the shift lever to the neutral position.

  1. Jack up the vehicle.

  1. Turn the ignition switch to ON.

  1. Check the voltage between the terminal of the combination meter and the body ground while the wheel is turned slowly.

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D1-17 - Body ground
    		Ignition switch ON
    (Turn wheel slowly)
    		Voltage generated intermittently
    Text in Illustration
    *a
    		Component with wire harness connected
    (Combination Meter Assembly)
    *b
    		Turn Wheel
    HINT:
    The output voltage should fluctuate up and down, similarly to the diagram, when the wheel is turned slowly.


NG
Go to step 6
OK

REPLACE COMBINATION METER ASSEMBLY (YARIS_NCP93 RM000000IN001JX.html)

6.CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - SPEEDOMETER SENSOR)

  1. Disconnect the D1 combination meter assembly connector.

  1. Disconnect the C21 speedometer sensor connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    D1-17 - C21-3 (SI)
    		Always
    		Below 1 Ω
    D1-17 - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE SPEEDOMETER SENSOR