Test Procedure

P1 PRELIMINARY DIAGNOSIS

Retrieve and record all DTCs.
Access the freeze frame data (if available) and record the DTC conditions.
Clear the PCM DTCs.
For F-650/F-750 and F-Series Super Duty,
Carry out the PCM self-test.
For all others,
Carry out the key on engine off (KOEO) self-test.
Carry out the key on engine running (KOER) self-test.

Are any DTCs retrieved?

Yes	No
For DTCs P062D or P062E, GO to P8. For all others, GO to P2.	Unable to duplicate the condition. CHECK for a loose connection, and damaged or corroded terminals. WIGGLE the harness attempting to recreate the concern. REPAIR as necessary. RETURN to SYMPTOM CHARTS for further direction.

P2 CHECK THE SUSPECT FUEL INJECTOR INTERNAL RESISTANCE

NOTE: Only the suspect fuel injector or bank of fuel injectors indicated by the DTC needs to be diagnosed. For F-150, when diagnosing a fuel injector or fuel injector circuit concern, bank 1 refers to cylinder numbers 1, 2 and 3, bank 2 refers to cylinder numbers 4, 5 and 6. For Transit Connect, when diagnosing a fuel injector or fuel injector circuit concern, bank 1 refers to cylinder numbers 1, 2, 3 and 4. For all others, when diagnosing a fuel injector or fuel injector circuit concern, bank 1 refers to cylinder numbers 1, 4, 6 and 7, bank 2 refers to cylinder numbers 2, 3, 5 and 8.

Ignition OFF.
Suspect Fuel Injector connector disconnected.
Measure the resistance between:

(+) Suspect Fuel Injector Connector, Component Side	(-) Suspect Fuel Injector Connector, Component Side
INJRTN	INJ

Is the resistance between 150K - 210K ohms?

Yes	No
GO to P3.	INSTALL a new Fuel Injector. REFER to the appropriate Fuel Charging and Controls article. Clear the PCM DTCs. REPEAT the self-test.

P3 CHECK THE SUSPECT FUEL INJECTOR FOR A SHORT TO THE CASE

Measure the resistance between:

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

Are the resistances greater than 10K ohms?

Yes	No
GO to P4.	GO to P9.

P4 CHECK THE SUSPECT INJ AND INJRTN CIRCUITS FOR AN OPEN

PCM-E connector disconnected.
Measure the resistance between:

(+) Suspect Fuel Injector Connector, Harness Side	(-) PCM-E Connector, Harness Side
INJ	INJ
INJRTN	INJRTN

Are the resistances less than 5 ohms?

Yes	No
GO to P5.	REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.

P5 CHECK THE SUSPECT INJ AND INJRTN CIRCUITS FOR A SHORT TO GROUND

Measure the resistance between:

(+) Suspect Fuel Injector Connector, Harness Side	(-)
INJ	Ground
INJRTN	Ground

Are the resistances greater than 10K ohms?

Yes	No
GO to P6.	REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.

P6 CHECK THE SUSPECT INJ AND INJRTN CIRCUITS FOR A SHORT TO VOLTAGE

Ignition ON, engine OFF.
Measure the voltage between:

(+) Suspect Fuel Injector Connector, Harness Side	(-)
INJ	Ground
INJRTN	Ground

Is any voltage present?

Yes	No
REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.	GO to P7.

P7 CHECK FOR THE INJ AND INJRTN CIRCUITS SHORTED TOGETHER

Ignition OFF.
Measure the resistance between:

(+) Suspect Fuel Injector Connector, Harness Side	(-) Suspect Fuel Injector Connector, Harness Side
INJ	INJRTN

Is the resistance greater than 10K ohms?

Yes	No
GO to P8.	REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.

P8 CHECK THE VPWR CIRCUIT FOR VOLTAGE

Ignition OFF.
PCM-B connector disconnected.

Connect a 5 amp fused jumper wire between the following:

Point A PCM-B Connector, Harness Side	Point B
PCMRC	Ground

Measure the voltage between:

(+) PCM-B Connector, Harness Side	(-)
VPWR	Ground

Is the voltage greater than 10.5 V?

Yes	No
GO to P9.	CHECK the generator circuitry and operation. REFER to the appropriate Charging System article to diagnose any generator related concerns. If there are no generator system concerns, REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.

P9 CHECK THE FUEL FOR CONTAMINATION

Check the fuel for contamination. Refer to DIAGNOSTIC PROCEDURES and carry out the Sufficient Clean Fuel Test.

Is the fuel contaminated?

Yes	No
CARRY OUT the Diesel Fuel System Contamination Repair/Flushing procedure. REFER to the appropriate Fuel System, General Procedures article. Clear the PCM DTCs. REPEAT the self-test.	For DTCs P1291 or P1292, INSTALL new Fuel Injectors for all cylinders and a new Fuel Return Line. REFER to the appropriate Fuel Charging and Controls article. Clear the PCM DTCs. REPEAT the self-test. For all others, INSTALL a new Fuel Injector as necessary. REFER to the appropriate Fuel Charging and Controls article. Clear the PCM DTCs. REPEAT the self-test.