Key On Engine Off (KOEO) Injector Electrical Self-Test (Click Test)
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The KOEO injector electrical self-test (click test) is an on-demand functional test of the fuel injection control module (FICM) carried out with the key on and the engine off. This test determines if the injector circuits and solenoids are electrically operating without fault. All injectors click (audible feedback of the injector solenoids energizing the injector valves) together. Then each injector, 1 through 8, is cycled approximately one second in sequence. This process is repeated 3 times during the entire test. If a fault is detected by the FICM, a CAN message is sent to the PCM. Corresponding fault DTCs are displayed at the end of the self-test.