Engine Controls - Tests W/Codes - 5.8L EEC-IV: Introduction

NOTE: This article covers 5.8L with Federal emissions and Gross Vehicle Weight (GVW) over 8500 lbs. For testing on all other Step 5.8L pickup models, refer to TESTS W/O CODES - 5.8L EEC-V article.

Perform all steps in the BASIC TESTING - 5.8L article. If no fault is found, proceed with self-diagnostics. If no diagnostic trouble codes or only pass codes (system functioning properly) found during self-diagnostics, proceed to TESTS W/O CODES - 5.8L EEC-IV article for diagnosis by symptom.