Engine Controls - Basic Testing - Gasoline: Introduction

Following diagnostic steps can help prevent overlooking a simple problem. Also use this article to begin diagnosis for a no-start condition. First step in diagnosing any driveability problem is verifying customer's complaint with a test drive under conditions during which problem reportedly occurs.

Before entering self-diagnostics, perform a careful and complete visual inspection. Most driveability or no-start problems are not related to computerized engine control systems, but are in fact simple mechanical, electrical, fuel or vacuum related faults. Most engine control problems are results of mechanical breakdowns, poor electrical connections or damaged or misrouted vacuum hoses. Before condemning computerized engine control system, perform each test listed in this article.