Key On Engine Running (KOER) Self Test Description

The Engine Running (ER) 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 response to them. On some models, the technician is required to turn the steering wheel and depress the brake after the engine ID code is displayed. If the vehicle is equipped with a Overdrive Cancel Switch (OCS), the switch must be cycled after the ID code is displayed to test the ability of the EEC-IV system to detect a state change in the OCS.