Actron CP9190 manual Koeo Procedure, Code 12 will look like, Code 23 will look like

GM Historic (OBD I) Diagnostics

✓If CHECK ENGINE light is functional, the Field Service screen is displayed. Pressing ENTER will toggle the short to Pins A and B On and Off.

✓Continue with either the KOEO procedure or KOER procedure.

Field Service

Field Service: Off

Press ENTER to turn Field Service On.

✓ While in Field Service mode, no new DTCs are stored in the vehicle’s memory.

	KOEO Procedure
	✓ In the KOEO Procedure, Field Service can check relays, solenoids
	and the idle speed motor, and obtain DTCs using the CHECK
	ENGINE light.
	1) Turn ignition key on but do not start engine.
	2) On Scan Tool, place Field Service On.
	3) The CHECK ENGINE light begins to flash codes. Each DTC is
	displayed three (3) times. The DTCs are displayed starting with
5	the lowest numbered one. After all DTCs are displayed, the
	sequence keeps repeating until the ignition key or Field Service

mode is turned OFF.

❒Count the number of times the CHECK ENGINE light flashes to obtain DTCs. The first digit is sent first. A short pause sepa- rates digits while a long pause separates each DTC. All codes contain 2 digits.

❒DTC 12 (No RPM reference pulse) should display first since the engine is not running. If not, problems exist in the PCM or CHECK ENGINE light circuitry.

Code 12 will look like:

FLASH-pause-FLASH-FLASH — long pause.

Code 23 will look like:

FLASH-FLASH-pause-FLASH-FLASH-FLASH — long pause.

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