Key On Engine Running (KOER) Self Test Description

The Key On Engine Running (KOER) portion of the quick test indicates that it has started by sending an engine identification code. It then tests inputs and EEC-IV controlled functions by forcing various conditions and looking for expected engine responses. A single output pulse (displayed as a code 10) is sent as a signal to goose the throttle, during which inputs are tested for dynamic response. If no rpm change is detected, a special code (77) is sent to indicate that the test was incorrectly performed. When the goose test has been completed, fault (on-demand/hard) codes will be displayed. On some models, the technician is required to turn the steering wheel and depress the brake pedal after the engine ID code is displayed.