Key On Engine Running (KOER) Diagnostic Test

1994 PCED OBDI-A

SECTION 18A: Diesel Diagnosis — 7.3L DI Engine

5.: Key On Engine Running (KOER) Diagnostic Test

Apply parking brake.
Place shift lever firmly in neutral.
Block drive wheels.
Connect Super STAR II to the Data Link Connector (DLC) in order to run self-test.

Is vehicle prepared to run self-test?

Yes	No
GO to Diagnostic Sub-Routine 5.2.	REPEAT this test step.

Turn all accessories off.
Run engine until engine oil temperature is at a minimum temperature of 80°C (176°F).
Latch Star test button ON (ground STI).
After a Code 50 is transmitted, depress and release the following switches:

Note: Stab firmly to activate brake pressure switch.

At the end of the switch test the PCM will perform ICP and EBP test steps.
Depressing and releasing the brake pedal after a test step will stop the test and allow the PCM to transmit codes.

Are diagnostic codes being transmitted?

Yes	No
RECORD codes. REFER to Diagnostic Trouble Code description chart. GO to the proper pinpoint test. Note: KOER cylinder contribution test will follow automatically. GO to 5.3.	KOER aborted. CHECK Star Tester Connections. RETEST. If OK and no DTC codes are retrieved, GO to KOEO test.

Yes

RECORD codes. REFER to Diagnostic Trouble Code description chart. GO to the proper pinpoint test.

Note: KOER cylinder contribution test will follow automatically.

GO to 5.3.

KOER aborted. CHECK Star Tester Connections. RETEST. If OK and no DTC codes are retrieved, GO to KOEO test.

Note this test will run automatically after the KOER test.

Codes 51 through 58 will be transmitted to tell you the cylinder is under pressure.
DTCs will be transmitted at the end of this test.

Are DTCs received?

Yes	No
RECORD codes. REFER to Diagnostic Trouble Code description chart. GO to proper pinpoint test.	CHECK Star Tester Connections. RERUN Test.