Engine Controls - System/Component Tests - 7.3L Diesel: Introduction
Since many computer-controlled and monitored components set a Diagnostic Trouble Code (DTC) if they malfunction, perform QUICK TEST in TESTS W/CODES - 7.3L DIESEL article. Service DTCs as necessary.
NOTE:
Testing individual components does not isolate short or open circuits. Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate shorted or open wiring harness.