Section 4 (Engine Control System & Engine Component Tests): Introduction

WARNING: This page is about a different car, the 2002 Jeep Wrangler, 2002 Jeep Liberty, and 2002 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

Before testing separate components or systems, follow proper workflow. See DIAGNOSTIC PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article. If no Diagnostic Trouble Codes (DTCs) are present and a no start condition exists, proceed to appropriate BASIC DIAGNOSTIC PROCEDURES article. If no DTCs are present and a driveability condition exists, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).

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