Section 142 (Engine Controls - System/Component Tests - 4.0L): Introduction

WARNING: This page is about a different car, the 1994 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: For Grand Cherokee with 5.2L engine, see appropriate SYSTEM/COMPONENT TESTS - 5.2L article in the ENGINE PERFORMANCE section.

Before testing separate components or systems, perform procedures in appropriate BASIC TESTING - 4.0L article in this section below. Since many computer-controlled and monitored components set a trouble code if they malfunction, also perform procedures in TESTS W/CODES - 4.0L article in this section.

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.