Engine Controls - System/Component Tests: Introduction

Before testing separate components or systems, it is highly recommended that all procedures listed in BASIC TESTING article be performed. Since many computer controlled and monitored components will set a trouble code if they malfunction, it is also recommended that self-diagnosis be performed. See appropriate TESTS W/CODES article.

NOTE: Testing individual components does not isolate possible shorts or opens in the control harness of electronically controlled systems. Use an ohmmeter and appropriate wiring diagram in WIRING DIAGRAMS to isolate shorts or opens in harness. All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in testing procedures.