Engine Controls - System/Component Tests - Diesel: Introduction

Since many computer-controlled and monitored components set a Diagnostic Trouble Code (DTC) if they malfunction, also perform procedures in TESTS W/CODES - 1.9L DIESEL article. In most instances, a scan tool must be used to test systems and/or components. See ENTERING ENTERING SELF-DIAGNOSTICS in TESTS W/CODES - 1.9L DIESEL article for additional scan tool operating instructions.

NOTE: Testing individual components does not isolate short or open circuits. Perform all voltage tests with a Digital Volt-Ohmeter (DVOM) with a minimum 10-megohm input impedence, unless stated otherwise in test procedure. Use ohmmeter to isolate shorted or open wiring harness.