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Entering On-Board Diagnostics (Using Voltmeter)

  1. Before entering on-board diagnostics, refer to PRETEST INSPECTION  in this article. Turn ignition switch to OFF position. Locate self-diagnostic connector. See SELF-DIAGNOSTIC TEST CONNECTOR LOCATION  table. Using an analog voltmeter, connect voltmeter positive lead to self-diagnostic connector terminal No. 1 and negative lead to terminal No. 12 (ground). See Figure .
  2. Turn ignition switch to ON position and disclosure of ECU memory will begin. If 2 or more systems are non-functional, they are indicated by order of increasing code number. Indication is made by 12-volt pulses of voltmeter pointer. A constant repetition of short 12-volt pulses indicates system is normal. If system is abnormal, voltmeter will pulse between zero and 12 volts.
  3. Signals will appear on voltmeter as long and short 12-volt pulses. Long pulses represent tens; short pulses represent ones. For example 4 long pulses and 3 short pulses indicates Code 43. See Fig 1 and Fig 2 . After recording abnormal code(s), perform necessary repair.
  4. After repair, turn ignition off and disconnect negative battery cable for 10 seconds to erase ECU memory. Reconnect power supply and repeat self-diagnostics to confirm repair.
    SELF-DIAGNOSTIC TEST CONNECTOR LOCATION

    Application Location
    Colt, Colt 200, Colt Wagon & Summit
    1.5L Next to fuse block
    1.6L Right kick panel
    Colt Wagon & Colt Vista 1.8L & 2.0L SOHC Next to fuse block
    Eclipse Next to fuse block
    Galant Left kick panel
    Mirage Left kick panel
    Montero Inside top of glove box
    Precis Left kick panel
    Fig 1: Diagnostic Fault Chart (1 of 2)
    G90J15361Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    Fig 2: Diagnostic Fault Chart (2 of 2)
    G90A15362Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.