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Home >> Toyota >> 2004 >> Tundra Base, Standard >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Infotainment >> Audio And Visual System - Diagnostics >> Circuit Inspection >> 3. Audio system cannot be operated using steering pad switch. >> Inspection Procedure
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Inspection Procedure

  1. Check steering pad switch. 

    PREPARATION: 

    Disconnect the steering pad switch connector.

    CHECK: 

    Check the resistance of the steering pad switch connector.

    OK: 

    TESTER CONNECTION SPECIFIED CONDITION

    Tester Connection Condition Specified Condition
    AU1 (C16-12) - EAU (C16-10) No switch pushed Approximately 100 kΩ
    AU1 (C16-12) - EAU (C16-10) SEEK + switch pushed Below 1 Ω
    AU1 (C16-12) - EAU (C16-10) SEEK - switch pushed Approximately 0.3 Ω
    AU1 (C16-12) - EAU (C16-10) VOL + switch pushed Approximately 1 kΩ
    AU1 (C16-12) - EAU (C16-10) VOL - switch pushed Approximately 3.2 kΩ
    AU2 (C16-11) - EAU (C16-10) No switch pushed Approximately 100 kΩ
    AU2 (C16-11) - EAU (C16-10) MODE switch pushed Below 1 Ω
    Fig 1: Identifying Steering Pad Switch Connector Terminals EAU, AU2 And AU1
    G02929901Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Replace steering pad switch. 
    2. OK: Go To Next Step 
  2. Check wire harness and connector (Radio and player - Steering pad switch). 

    PREPARATION: 

    Disconnect the radio and player connector and the steering pad switch connector.

    CHECK: 

    Check the resistance of the wire harness side connectors.

    OK: 

    Double cab (w/ Rear entertainment system and 8 speakers): 

    TESTER CONNECTION SPECIFIED CONDITION

    Tester Connection Specified Condition
    SW1 (R5-7) - AU1 (C16-12) Below 1 Ω
    SW2 (R5-8) - AU2 (C16-11) Below 1 Ω
    GND (R5-6) - EAU (C16-10) Below 1 Ω

    Except double cab (w/ Separate type amplifier (w/ VSC)): 

    TESTER CONNECTION SPECIFIED CONDITION

    Tester Connection Specified Condition
    SW1 (R13-7) - AU2 (C16-12) Below 1 Ω
    SW2 (R13-8) - AU2 (C16-11) Below 1 Ω
    GND (R13-6) - EAU (C16-10) Below 1 Ω

    Except double cab (w/ Separate type amplifier (w/o VSC) and w/ Built-in type amplifier): 

    TESTER CONNECTION SPECIFIED CONDITION

    Tester Connection Specified Condition
    SW1 (R11-7) - AU2 (C16-12) Below 1 Ω
    SW2 (R11-8) - AU2 (C16-11) Below 1 Ω
    GND (R11-6) - EAU (C16-10) Below 1 Ω
    1. NG: Repair or replace harness and connector. 
    2. OK: Replace radio and player.