Perform Key On Engine Running (KOER) Test

PURPOSE
To determine if the Powertrain Control Module (PCM) has detected any fault conditions that would cause a performance problem while the engine is running. This test also verifies the operation of various switches as described in the procedure below and will perform 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 and then measures the result. If a predetermined threshold is not reached, a fault code will be generated.

The cylinder contribution test can also be accessed after the completion of the switch tests and the step tests.

Equipment Hook-up:

RECOMMENDED PROCEDURE
- Engine must be up to minimum temperature of 176°F (80°C) and not exceed 242°F (117°C).
- Charging system voltage must be greater than 12.5 volts.
- Turn all accessories OFF.
- The engine must be running, the glow plugs should be cycled OFF.
- Latch Super STAR II test button ON (ground STI).
- After code 50 is transmitted, depress and release the following switches:
- accelerator pedal (must depress and release first)
- cruise control ON, OFF, RESUME, SET/ACCEL, COAST
- emergency brake
- clutch pedal
- brake pedal (must depress and release last)
- After the switch tests are performed the PCM will perform the Injection Control Pressure (ICP) and Exhaust Back Pressure (EBP) step tests.
- After the step tests are complete the PCM will automatically begin the cylinder contribution tests unless aborted by depressing the brake pedal.
- To abort code transmission and go directly to the step tests, depress and release the brake pedal twice after code 50 is transmitted (ignore resultant switch faults).

NOTE: The engine will run rough during the KOER Step Tests.

TOOLS REQUIRED
Rotunda Super STAR II Tester 007-0041B