Engine Controls - Basic Testing: Introduction
The following diagnostic steps will help prevent overlooking a simple problem. This is also where to begin diagnosis for a no-start condition.
The first step in diagnosing any driveability problem is verifying the customer's complaint with a test drive under the conditions 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 computerized system, perform each test listed in this article.
NOTE:
Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure.
NOTE:
Before disconnecting battery or removing radio fuse, obtain anti-theft code for radio from vehicle owner. After battery is reconnected, CODE will appear on radio display. Enter 5-digit code to restore radio operation. If code is entered incorrectly 3 times, leave radio on at least one hour, then enter code correctly. Any time radio power is lost, pre-selected radio stations will have to be reset. For more information, see owners manual.