Engine Controls - System & Component Testing - Ranger: Introduction

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

For 2.5L vehicles, see BASIC TESTING - 2.5L .
For 3.0L vehicles, see BASIC TESTING - 3.0L .
For 4.0L vehicles, see BASIC TESTING - 4.0L .

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

For 2.5L vehicles, see TESTS W/CODES - 2.5L .
For 3.0L vehicles, see TESTS W/CODES - 3.0L .
For 4.0L vehicles, see TESTS W/CODES - 4.0L .

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.