Section 6 (Engine Controls - Tests W/O Codes - 4.0L): Introduction

WARNING: This page is about a different variant/trim than selected.

Before diagnosing symptoms or intermittent faults, perform BASIC DIAGNOSTIC PROCEDURES in the BASIC TESTING - 4.0L article and SELF-DIAGNOSTICS TESTS in the TESTS W/CODES - 4.0L article. Use this article to diagnose driveability problems existing when a hard fault code is not present.

NOTE: Some driveability problems may have been corrected by manufacturer with a revised Powertrain Control Module (PCM). Check with manufacturer for latest PCM application.

Symptom checks can direct the technician to malfunctioning component(s) for further diagnosis. A symptom should lead to a specific component or system test and/or adjustment.

Use intermittent test procedures to locate driveability problems that DO NOT occur when the vehicle is being tested. These test procedures should also be used if a soft (intermittent) trouble code was present, but no problem was found during self-diagnostic testing.

NOTE: For specific testing, see the SYSTEM/COMPONENT TESTS article. For specifications, see the ADJUSTMENTS - 4.0L or the SPECIFICATIONS - 4.0L article.