Engine Controls - System & Component Testing: Introduction
Before testing separate components or systems, perform a visual inspection. Since many computer-controlled and monitored components set a trouble code if they malfunction, also perform procedures in appropriate SELF-DIAGNOSTICS article.
NOTE:
Testing individual components does not isolate shorts or opens. Perform all resistance tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.