11. Carry Out The Key On Engine Running (KOER) On-Demand Self-Test: Purpose:: Notes
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The purpose of this test is to determine if the PCM has detected any fault conditions that would cause a performance problem while the engine is running. The KOER self-test will carry out step tests on the injection control pressure system and the exhaust back pressure system.
Step tests are PCM controlled tests where the PCM commands a specific exhaust back pressure or injection control pressure (ICP) and then measures the result. If a predetermined threshold is not reached, a DTC will be generated. This test can be carried out at any engine temperature.