Key On, Engine Off (KOEO) Self-Test

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.