Engine Controls - Tests W/O Codes: Introduction

Before diagnosing any symptoms or intermittent fault conditionss, perform test procedures in both the BASIC TESTING and the TESTS W/CODES articles in this section. 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 computer calibration chip or electronic control unit. Check with manufacturer for latest chip or control unit application.

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

Use intermittent test procedures to locate driveability problems that DO NOT occur when the vehicle is being tested.

NOTE: For specific component or system test procedures, see the SYSTEM/COMPONENT TESTS article. For specifications, refer to the SPECIFICATIONS article. For tune-up procedures, refer to the ADJUSTMENTS article.