FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Key On Engine Running (KOER) Self Test Description


The Key On Engine Running (KOER) test performs various Electronic Engine Control (EEC-IV) functions and looks for expected engine response. The KOER test examines the fuel system, selected sensors, EGR system, idle speed control, knock detection system and dynamic system response during their normal operating conditions to determine if any problems or malfunctions exists.