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Inspection Procedure

  1. Check the Mayday switch. 

    PREPARATION: 

    Disconnect the Mayday switch connector.

    CHECK: 

    MAYDAY SWITCH CONNECTORS TERMINALS CONTINUITY

    Switch position Tester connection Specified condition
    Service Play back Record 1 - 2 Continuity
    Emergency Volume UP Volume DOWN 2 - 3 Continuity
    Fig 1: Identifying Mayday Switch Connector Terminals
    G03138565Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    There is a continuity when switch is pressed, and no continuity when not pressed. 

    1. NG : Replace the Mayday switch. 
    2. OK : Go to next step. 

  2. Check for open and short circuit in harness and connector between Mayday ECU and Mayday switch. 
    1. NG : Replace or repair wire harness connector. 
    2. OK : Replace the Mayday ECU. 
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