Key On, Engine Off (KOEO) Self-Test
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2002 Lincoln Navigator, 2002 Ford Expedition, 2001 Lincoln Navigator, 2001 Ford RV Cutaway, and 2001 Ford Pickup. 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 input and output devices 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.