Engine Controls - System & Component Tests - EEC-V - Gasoline: Introduction: Notes

NOTE: References to Econoline include Cutaway and RV Cutaway. References to F250-550 Super Duty Pickup include Cab & Chassis.

NOTE: Testing individual components does not isolate shorted 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. For identification of circuits and terminals referenced in test procedures, see WIRING DIAGRAMS article.

Before testing separate components or systems, perform appropriate procedures in BASIC DIAGNOSTIC PROCEDURES - CARS or BASIC DIAGNOSTIC PROCEDURES - TRUCKS - EXCEPT DIESEL article. Computer-controlled and monitored components should set a Diagnostic Trouble Code (DTC) if they malfunction. Check for Key On Engine Off (KOEO), Key On Engine Running (KOER) and/or Continuous Memory DTCs prior to testing individual components. Perform QUICK TEST procedures in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article. In many cases a circuit that is open, or shorted to ground or power can be at fault. Component replacement is only suggested after testing and passing circuits and control devices. A component test may direct you to a system test in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article to help avoid replacement of a good component. If the component can be tested properly on its own, it will be included here.