Engine Controls - Tests W/Codes - EEC-IV (3.0L): Introduction

Perform all steps in BASIC TESTING - 3.0L article in the ENGINE PERFORMANCE section. If no fault is found while performing steps in BASIC TESTING , proceed with self-diagnostics. If no diagnostic trouble codes or only pass codes (system functioning properly) are found during self-diagnostics, proceed to TESTS W/O CODES - EEC-IV article in the ENGINE PERFORMANCE section for diagnosis by symptom.