Engine Controls - System & Component Testing: Introduction

Before testing separate components or systems, perform procedures in BASIC DIAGNOSTIC PROCEDURES article. Since many computer-controlled and monitored components set a Diagnostic Trouble Code (DTC) if they malfunction, also perform procedures in appropriate SELF-DIAGNOSTICS article.

NOTE: Before disconnecting battery, obtain anti-theft code and presets for radio. After battery is reconnected, CODE will appear on radio display. Enter 5-digit anti-theft code using select buttons and radio will begin working. If code is entered wrong 3 times, leave radio on at least one hour and enter code correctly. Any time radio power is lost, pre-selected radio stations will have to be reset.

NOTE: Testing individual components does not isolate short or open circuits. Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.