Key On-Engine Off (KOEO) Self-Test
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.
The first code shown is the On Demand code, the second code is a Separator code and the third code is the Continuous code. The On Demand first digit is indicated by a pulse, then the needle drops to zero for 2 seconds, then the second digit of the code is displayed. After 6-9 seconds, the Separator code (single digit) will be displayed for 1/2 second. After 6-9 seconds, the first digit of the Continuous code will be displayed, the needle will drop to zero for 2 seconds, then the second digit of the Continuous code will display.