Key On Engine Off (KOEO) On Demand Self-Test
WARNING: This page does not describe the selected car, but rather 27 other vehicles, including the 2021 Lincoln Navigator, 2021 Lincoln Nautilus, 2021 Lincoln Corsair, 2021 Lincoln Aviator, and 2021 Ford Transit-350 HD. 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 ignition ON and the engine OFF. This test carries out checks on certain sensor and actuator circuits. A concern 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 the scan tool.