Engine Controls - Tests W/Codes - 3.3L CNG: Introduction

If no troubles were found while performing BASIC DIAGNOSTIC PROCEDURES - CNG, proceed with self-diagnostics. If no trouble codes or only pass codes are present after entering self-diagnostics, proceed to TEST NTC-1A  and TEST NS-1A  in this article, and TESTS W/O CODES - CNG article in the ENGINE PERFORMANCE section for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).