Key On Engine Off (KOEO) On-Demand Self-Test
WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2006 Mercury Mountaineer, 2006 Mercury Monterey, 2006 Mercury Montego, 2006 Mercury Milan, and 2006 Mercury Mariner. However, it is still accessible from the selected car via links, so may be relevant.
The KOEO on-demand self-test is a functional test of the PCM carried out on-demand with the key on and the engine off. This test will carry out checks on certain sensor and actuator circuits. A fault must be present at the time of testing for the KOEO self-test to detect the concern. When a concern is detected, a DTC is output on the data link at the end of the test as requested by a diagnostic tool.