Engine Controls - Tests W/Codes: Introduction

NOTE: Description of self-diagnostic system is based on 535i (DME 1.3 system). The self-diagnostic system for 325 and 525i models (DME 3.1) operates similarly to DME 1.3 system. Only those descriptions provided by manufacturer are included in this article.

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed with self-diagnostics. If no fault codes or only pass codes are present after entering self-diagnostics, proceed to the 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 otherwise in testing procedures.