Engine Controls - Tests W/Codes: Introduction

NOTE: Diagnostic information for E420 is not available. Limited diagnostic information is available for HFM-SFI and LH-SFI equipped vehicles.

If no faults were found while performing preliminary inspection, proceed with SELF-DIAGNOSTIC SYSTEM . If no fault codes or only pass codes are present, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).

NOTE: All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless specifically stated different in testing procedures.