Audio And Visual System (For Radio And Display Type) Speed Signal Circuit


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK OPERATION OF SPEEDOMETER

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

AUDIO AND VISUAL SYSTEM (for Radio and Display Type) - Speed Signal Circuit


DESCRIPTION

The vehicle speed signal consists of pulses sent to the combination meter assembly from the speedometer sensor. This circuit is necessary for the ASL (Auto Sound Levelizer) built into the radio and display receiver assembly. Speed signals are received from the combination meter and used for the ASL.
The ASL function automatically adjusts the sound data in order to enable the listener to hear the sound of the audio system clearly 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. The signal is changed to a pulse signal at the transistor in the combination meter. Each ECU controls its 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, both systems in the diagram below will not operate normally.

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Audio Visual.Audio And Visual System (For Radio And Display Type).Audio And Visual System (For Radio And Display Type)  Speed Signal Circuit


INSPECTION PROCEDURE

1.CHECK OPERATION OF SPEEDOMETER
  1. Drive the vehicle and check if the function of the speedometer in the combination meter is normal.

    OK:
    Actual vehicle speed and the speed indicated on the speedometer are the same.
    HINT:
    The vehicle speed sensor is functioning normally when the indication on the speedometer is normal.


NG
GO TO METER / GAUGE SYSTEM (Toyota Fortuner RM0000011IT01AX.html)
OK


2.CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER - COMBINATION METER)
  1. Disconnect the R19 radio and display receiver assembly connector.

  1. Disconnect the C27 combination meter assembly connector.

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

    Standard Resistance:
    Tester Connection
    Condition
    Specified Condition
    R19-17 (SPD) - C27-6
    Always
    Below 1 Ω
    R19-17 (SPD) - Body ground
    Always
    10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY (Toyota Fortuner RM000003OQ9003X.html)