Engine Controls - Tests W/O Codes: Introduction

Before using this article to diagnose symptoms or intermittent faults, perform testing in BASIC TESTING article and TESTS W/CODES article. Use this article to diagnose driveability problems existing when a hard Diagnostic Trouble Code (DTC) 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.

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

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

NOTE: For specific testing procedures, see TESTS W/CODES article. For specifications, see ADJUSTMENTS or SPECIFICATIONS article.