Key On, Engine Off (KOEO) Self-Test
WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2002 Mercury Grand Marquis, 2002 Lincoln Town Car, 2002 Ford Crown Victoria, 2001 Mercury Mountaineer, and 2001 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.
KOEO self-test is a functional test of PCM performed with ignition switch turned to ON position, engine off. This test checks if PCM inputs and outputs are functioning electronically without any faults. KOEO self-test displays on-demand hard DTCs. These DTCs usually are electrical open and/or short circuits and must be serviced first, before any other type of DTCs. A fault must be present at time of testing for KOEO self-test to detect a fault.