Reading Self-Test Codes: Notes
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 1984 Ford RV Cutaway, 1984 Ford Pickup, 1984 Ford Econoline, 1984 Ford Cutaway, and 1984 Ford Club Wagon. However, it is still accessible from the selected car via links, so may be relevant.
Service codes are transmitted to the Self-Test Output connector. They are shown as voltage pulses on a Volt-Ohmmeter (VOM), or as numbers on the STAR tester.