Entering On-Board Diagnostics (Using Voltmeter)
NOTE:
Before proceeding with diagnosis, certain precautions must be followed. See PRETEST INSPECTION.
- Turn ignition off. Using an analog voltmeter, connect voltmeter positive lead to self-diagnostic connector terminal No. 1 and negative lead to terminal No. 12 (ground). Diagnostic connector is located next to junction block, above left kick panel. See Fig 1 .
- Ensure all accessories are off. 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. Signals will appear on voltmeter as long and short 12-volt pulses. Long pulses represent tens; short pulses represent ones.
- For example, one long sweep followed by a short pause followed by 4 short sweeps would indicate a Code 14. See Fig 2 . After recording abnormal codes, perform necessary repair according to appropriate diagnostic fault chart. See Figure .
- After repair, turn ignition off. Disconnect negative battery cable for 10 seconds to erase ECU memory. Reconnect negative battery cable and repeat self-diagnostics to confirm repair.