Engine Controls - Self-Diagnostics: Introduction

If no faults were found while performing BASIC TESTING procedures, proceed with self-diagnostics. If no fault codes or only pass codes are present after entering self-diagnostics, proceed to appropriate article for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.):

• For 1990 models, see TESTS W/O CODES article.
• For 1991 models, see TESTS W/O CODES article.