KOEO On-Demand Self-Test: Description
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2003 Mercury Sable, 2003 Mercury Mountaineer, 2003 Mercury Marauder, 2003 Mercury Grand Marquis, and 2003 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
KOEO on-demand 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. A fault must be present at time of testing for KOEO on-demand self-test to detect a fault.