Without Scan Tool

HOW TO DISPLAY AND READ DIAGNOSTIC TROUBLE CODES WITHOUT SCAN TOOL

CAUTION:
1) If the battery voltage is low, no trouble codes will be stored. Be sure to check the battery voltage before starting the test.
2) Diagnostic codes will be erased if the battery or the ECU harness is disconnected. Do not disconnect the battery before the diagnostic codes are read.
3) After checks and repairs are completed, disconnect the (-) ground cable for 15 seconds or more to make sure that the codes are erased.




1. Connect the voltmeter to the self diagnosis connector.
2. Turn on the ignition switch, and indication of electronic control unit memory contents will immediately start. If the system is in normal operating condition, the pointer of voltmeter indicates a normal pattern. If any abnormality is in the memory, the pointer of voltmeter will deflect, indicating an abnormal item as described in "Diagnosis chart".

After recording the abnormal item, check and repair each part according to the check items in "Diagnosis Chart"

3. When the defective parts have been repaired, disconnect the negative terminal of the battery cable for 15 seconds or more, reconnect it to make sure that the abnormal code has been erased.

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DIAGNOSIS CHARTS

**TSB # 9113003, DATED FEBRUARY 1991
There are two different wiring harnesses used on this vehicle. A poor connection at a crimp may be causing the check engine light to come on. Refer to the TSB for further information.