Engine Controls - System & Component Testing 3.0L & 3.4L: Introduction

Before testing separate components or systems, perform BASIC DIAGNOSTIC PROCEDURES in appropriate article:

For 3.0L vehicles, see BASIC TESTING - 3.0L .
For 3.4L vehicles, see BASIC TESTING - 3.4L .

Since many computer-controlled and monitored components set a Diagnostic Trouble Code (DTC) if they malfunction, also perform SELF-DIAGNOSTICS in appropriate article:

For 3.0L OHV gasoline vehicles, see TESTS W/CODES - 3.0L OHV GASOLINE .
For 3.0L OHV Flex-Fuel vehicles, see TESTS W/CODES - 3.0L OHV FLEX-FUEL .
For 3.0L DOHC vehicles, see TESTS W/CODES - 3.0L DOHC .
For 3.4L vehicles, see TESTS W/CODES - 3.4L .

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 shorted or open wiring harness.

NOTE: For identification of circuits and terminals referenced in test procedures, see appropriate WIRING DIAGRAMS article.