LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2004 >> RX 330 AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 439 (Audio System - Diagnostics) >> Pre-Check
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Section 439 (Audio System - Diagnostics): Pre-Check

WARNING: This page is about a different car, the 2005 Lexus RX 330. However, it is still accessible from the selected car via links, so may be relevant.
  1. DIAGNOSTIC CHECK 
    1. Starting Diagnostic Mode (All elements come on during the SW check mode)
      1. Turn off the audio system and turn the ignition switch to the ACC position. While pressing the preset switches "1" and "6" at the same time, press the "DISC" 3 times.
      2. Reference:
        • When the system enters the diagnostic mode, a beep sound is emitted 3 times and all the elements come on during the SW check mode.
        • It takes about 40 seconds to complete the check.
        • Turn all the elements in the LCD on.
        • When pressing the switch, confirm a beep sound is emitted.
        • Press the "SEEK TRACK (up)" button to enter the "Service Check Screen".
          Fig 1: Identifying Turn Off Audio System
          G03009135Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
    2. Service Check Screen
      1. Reference:

        In the service check mode, the system check and the diagnostic memory check are performed, and the check results are displayed in ascending order of the component codes (physical address).

        SERVICE CHECK SCREEN CHART

        Terms Meaning
        Component code (Physical address) Three-digit code (in hexadecimal) given to each device comprising AVC-LAN. Corresponding to its function, individual symbol is provided.
        Logical address Two-digit code (in hexadecimal) given to each function and device unit in each device comprising AVC-LAN.

        Code No. (physical address) List 

        EQUIPMENT NAME CHART

        Code No. (physical address) Equipment name
        190 Radio receiver assy (Audio head unit)
        440 Stereo component amplifier assy
        1F6, 16C Multi-display Controller Sub-assy
    3. Finishing Diagnostic Mode
      1. Press the "DISC" for 2 seconds or more, or turn the ignition switch off.
    4. Service Check Mode Result Display (for checking the current and the past system conditions)
      1. Press the "SEEK TRACK" switch to see the check result of each component.
        Fig 2: Identifying Seek Track Switch Display
        G03009136Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
      2. Check Result Display
        ORIGINAL LANGUAGE CHART

        Display Original Language Meaning Action to be taken
        good Good (normal) No DTCs are detected in both "System Check Mode" and "Diagnostic Memory Mode". -
        NCON No connection The system recognized the component when it was registered, but the component gives no response to the "Diagnostic Mode ON Request". Check the power source circuit and the communication circuit of the component indicated by the component code (physical address).
        ECHN Exchange One or more DTCs for "Exchange" are detected in either "System Check Mode" or "Diagnostic Memory Mode". Go to the detailed information mode to check the trouble area referring to the .
        OLD Old version Old DTC application is identified and DTC is detected in either "System Check Mode" or "Diagnostic Memory Mode". -
        NRES No response The device gives no response to any one of "System Check Mode ON Request", "System Check Result Request" and "Diagnostic Memory Request". Check the power source circuit and the communication circuit of the component indicated by the component code (physical address).
      3. To perform the service check again, press the preset switch "1".
    5. Detailed Information Mode (when displaying the DTC for a defective component)
      1. With "CHEC" or "ECHN" being displayed, press the preset switch "2" to go to the detailed information mode.
      2. Press the "SEEK TRACK" switch to display the "System Check Result (SYS)" and "Diagnostic Memory Response (CODE)".
        Fig 3: Identifying Detailed Information Mode Chart
        G03009137Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
      3. Displayed Items in Detailed Information Mode
        DETAILED INFORMATION MODE REFERENCE

        Division Code for DTC display Meaning The order of detailed information displayed when the "TUNE UP" switch is pressed. (The order is reversed when the "TUNE DOWN" switch is pressed.)
        SYS System check result is displayed. Logical address -->
        SYS System check result is displayed. DTC
        CODE Diagnostic memory check result is displayed. Logical address -->
        CODE Diagnostic memory check result is displayed. DTC -->
        CODE Diagnostic memory check result is displayed. Sub code -->
        CODE Diagnostic memory check result is displayed. Connection confirmation number -->
        CODE Diagnostic memory check result is displayed. The number of times of occurrence
      4. Check the trouble area referring to the DTC list.
      5. To return to the service check mode, press the preset switch "3".
    6. Clearing Individual DTC Memory (when clearing the memory of the DTC detected in the past individually)
      1. Press the preset switch "5" for 2 seconds or more while the "ECHN" is displayed in the service check mode or during the detailed information mode.

      HINT:

      • A beep sound is emitted once when the DTC memory is completely cleared.
      • When the DTC memory is cleared, only the component code (physical address) is displayed for the target component.
      • To check DTCs, press the preset switch "1" and perform the service check again.
    7. Clearing All DTC Memory (when clearing all the memory of the DTCs detected in the past)
      1. Start the diagnostic mode after repairing the trouble area.
      2. Press the preset switch "5" for 2 seconds or more. ("CLR" is displayed at this time.)

        HINT:

        • A beep sound is emitted once when the DTC memory is completely cleared.
        • When the DTC memory for all the components is cleared, only the component codes (physical address) are displayed.
      3. Press the preset switch "1" to perform the service check again, and check that no DTCs are displayed for all the component codes (physical address).
  2. IDENTIFICATION OF NOISE SOURCE 
    1. Identify the conditions under which the noise occurs, and check the noise filter on the relevant part.
      NOISE SOURCE REFERENCE

      Conditions under which noise occurs Noise type
      Noise increases when the accelerator pedal is depressed, but stops when the engine is stopped. Generator noise
      Noise occurs during A/C or heater operation. Blower motor noise
      Noise occurs when the vehicle accelerates rapidly on an unpaved road or after the ignition switch is turned on. Fuel pump noise
      Noise occurs when the horn switch is pressed and released or when pressed and held. Horn noise
      Quiet noise occurs while the engine is running, but stops when the engine is stopped. Ignition noise
      Noise occurs synchronously with the blink of the turn signal. Flasher noise
      Noise occurs during window washer operation. Washer noise
      Noise occurs while the engine is running, and continues even after the engine is stopped. Water temperature sensor noise
      Noise occurs during wiper operation. Wiper noise
      Noise occurs when the brake pedal is depressed. Stop light switch noise
      Others Static electricity stored on the vehicle
    2. Reference:
      • First ensure that the noise is not coming from the outside. Failure to do so makes noise source detection difficult and may lead to a misdiagnosis.
      • Noise should be removed in descending order of loudness.
      • Tuning the radio so that no station is received makes the noise more noticeable, making the recognition of the phenomenon easier.
scientia non olet · About LEMON Manuals