Engine Controls - System/Component Tests: Introduction

Before testing separate components or systems, perform procedures in BASIC TESTING article. Since many computer controlled and monitored components set a Diagnostic Trouble Code (DTC) if they malfunction, also perform procedures in TESTS W/CODES - MOTRONIC 5.2 SYSTEM or TESTS W/CODES - TRIONIC SYSTEM articles.

NOTE: Testing of individual components does not isolate possible shorts or opens. Unless stated otherwise in testing procedures, perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with minimum 10-megohm input impedance. Use ohmmeter to isolate wiring harness shorts or opens.

Manufacturer recommends that all DTCs be retrieved and diagnostic command codes be entered with a scan tool, a proprietary device available from manufacturer.