Engine Controls - Tests W/Codes: Introduction
If no faults were found while performing BASIC TESTING , proceed with self-diagnostics. If no fault codes or only pass codes are present after entering self-diagnostics, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.).
CAUTION:
Use only a digital voltmeter, ohmmeter, or multimeter with high input impedance. The electrical characteristics of other types of test equipment may cause inaccurate results or damage to the electronic components.
NOTE:
The ignition must be OFF before disconnecting or connecting any electrical connections.