7. Carry Out The Key On Engine Running (KOER) On-Demand Self-Test

7. CARRY OUT THE KEY ON ENGINE RUNNING (KOER) ON-DEMAND SELF-TEST

Purpose:
The purpose of this test is to determine if the PCM has detected any fault conditions that would cause a performance concern while the engine is running. The KOER self-test carries out step tests on the high and low fuel pressure systems and the exhaust pressure system.

Step tests are PCM controlled tests where the PCM commands a specific exhaust pressure or fuel rail pressure (FRP) and then measures the result. If a predetermined threshold is not reached, a DTC is generated. This test can be carried out at any engine temperature.

Carry Out The KOER On-Demand Self-Test
- The self-test verifies the FRP, exhaust gas recirculation (EGR), and turbocharger systems performance.







Recommended Procedure:

NOTE: The engine runs rough during this test.

Connect the scan tool. Turn off all accessories. If the vehicle is equipped with a PTO system or auxiliary idle control, it must be turned off to carry out the self-test.
- Carry out the necessary vehicle preparation and visual inspection. Refer to Diagnostic Methods, Quick Test Operation. Quick Test Description
- Refer to the scan tool operating manual for instructions.
- Ignition ON, engine running.
- Follow the operating instructions from the diagnostic menu.
- Carry out a KOER On Demand Self-Test.
- Record the DTCs and refer to the appropriate pinpoint test.

Tools Required:
Scan tool