Engine Controls - Basic Testing: Introduction

The following diagnostic steps help prevent overlooking simple problems and begin diagnosis for a no-start condition.

The first step in diagnosing any driveability problem is to verify the complaint. Test drive the vehicle under the conditions in which the problem reportedly occurred.

Before entering self-diagnostics, perform a careful and complete visual inspection. Most engine control problems result from mechanical breakdowns, poor electrical connections or damaged/misrouted vacuum hoses. Before condemning the computerized system, perform each test listed in this article.