Engine Controls - Tests W/Codes - 4.9L: Introduction
If no trouble codes were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed with self-diagnostics. If no trouble codes or only pass codes are present after entering self-diagnostics, proceed to TESTS W/O CODES article in the ENGINE PERFORMANCE section for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).
NOTE:
On vehicles equipped with Multiport Fuel Injection (MFI), fuel system may also be referred to as Port Fuel Injection (PFI).