Test Procedure

WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

AR1 PRELIMINARY DIAGNOSIS FOR DIAGNOSTIC TROUBLE CODES (DTCS) P0300 THROUGH P0308

Are DTCs P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 or P0308 present?

Yes	No
GO to AR3.	GO to AR2.

AR2 RECREATE THE MISFIRE SYMPTOM USING FREEZE FRAME AND CUSTOMER INFORMATION

NOTE: To recreate the original conditions that set the DTC or caused the symptom, the vehicle may require driving.

Access the misfire freeze frame data (if available) and record the operating conditions.
Obtain information from the customer information worksheet or any other available data from the customer.
Recreate the misfire symptom using the freeze frame and customer information.

Can the symptom be recreated?

Yes	No
GO to AR3.	Unable to duplicate or identify the concern at this time. REFER to NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX , if a driveability concern exists.

AR3 CHECK FOR OTHER NON-MISFIRE CONTINUOUS MEMORY DTCS

Are there any non-misfire continuous memory DTCs present?

Yes	No
DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .	GO to AR4.

AR4 CHECK FOR DTCS

Carry out the PCM KOEO self-test.
Carry out the PCM KOER self-test.
Carry out the injector electrical self-test.

Are any DTCs present?

Yes	No
DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .	GO to AR5.

AR5 CHECK THE LOW PRESSURE FUEL SYSTEM

Ignition ON, engine OFF.
Access the PCM and monitor the LP_FUEL_SW (MODE) PID.
Access the PCM and control the FPL_CMD (MODE) PID.
Command the fuel pump ON.

Does the PID state change?

Yes	No
GO to AR6.	GO to Pinpoint Test MA .

AR6 RELATIVE COMPRESSION TEST

Carry out the Relative Compression Test. Refer to the scan tool manufacturer's manual for specific information on the scan tool setup, operation, and specific cables and adapters required.

Do all cylinders pass the test?

Yes	No
GO to AR7.	GO to AR9.

AR7 CYLINDER POWER BALANCE CHECK

Carry out the Power Balance Test. Refer to the scan tool manufacturer's manual for specific information on the scan tool setup, operation, and specific cables and adapters required.

Are all cylinders contributing correctly during the power balance test?

Yes	No
GO Pinpoint Test M .	GO to AR8.

AR8 CHECK THE SUSPECT FUEL INJECTOR RESISTANCE AT THE FUEL INJECTOR

NOTE: Only diagnose the fuel injectors for the cylinders identified as weak during the power balance test.

Suspect Fuel Injector connector disconnected.

Measure the resistance between:

(+) Suspect Fuel Injector Connector, Component Side	(-) Suspect Fuel Injector Connector, Component Side
Fuel Injector, Ground	Fuel Injector, Power

Is the resistance between 150K - 210K ohms?

Yes	No
GO to AR9.	GO to Pinpoint Test P .

AR9 CARRY OUT A CYLINDER COMPRESSION TEST ON THE SUSPECT CYLINDER

Carry out a visual inspection for the following mechanical concerns:
- push rods
- rocker arms
- valves
- valve springs
Carry out a cylinder compression test on the suspect cylinder. Refer to the appropriate Engine System - General Information article.

Are any concerns present?

Yes	No
REPAIR as necessary. Clear the PCM DTCs. REPEAT the self-test.	GO to AR10.

AR10 CHECK FOR LEAKING FUEL INJECTOR

Disconnect all the fuel injector electrical connectors.
Remove the glow plug from the suspect cylinder.
Crank the engine.
Observe the glow plug hole for a fuel mist.

Is there any fuel mist from the glow plug hole?

Yes	No
INSTALL a new Fuel Injector. REFER to the appropriate Fuel Charging and Controls article. Clear the PCM DTCs. REPEAT the self-test.	GO to Pinpoint Test M .