Test P: Misfire/Injector Drive Circuit Operation: Testing

WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, 2003 Ford Excursion, and 2003 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Do not pierce engine electrical wires or damage to the harness can occur.

CAUTION: The Powertrain Control Module (PCM) harness connectors must be properly seated and the connector latch properly attached to eliminate possible driveability concerns or a no-start condition. Installing PCM connectors on an angle may cause a bad connection, misdiagnosis and damaged components. Install the connector on where the lever pivots and seats itself. Apply light pressure to get the connector into position on the PCM lever to fully seat the connector.

NOTE: When the PCM engine harness connector is disconnected additional DTCs will be set. All DTCs must be cleared before returning the vehicle to service.

1) Preliminary Diagnosis

Perform a visual inspection. Connect the scan tool. Retrieve and record any continuous and on-demand DTCs. Clear the DTCs. Perform KOEO INJECTOR ELECTRICAL SELF-TEST under QUICK TEST. Are any DTCs retrieved? If yes, proceed as follows:
- For DTCs P0261, P0264, P0267, P0270, P0273, P0276, P0279 or P0282, go to next step.
- For DTCs P0262, P0265, P0268, P0271, P0274, P0277, P0280 or P0283, go to step 4).
- For DTCs P0301, P0302, P0303, P0304, P0305, P0306, P0307 or P0308, go to step 7).
- For DTCs P0263, P0266, P0269, P0272, P0275, P0278, P0281 or P0284, go to step 15).
If no, unable to duplicate condition. Check for loose connections, damaged or corroded pins. Wiggle harness attempting to recreate fault. See TROUBLE SHOOTING - NO CODES - DIESEL - 6.0L article if a driveability concern exists.

2) DTCs P0261, P0264, P0267, P0270, P0273, P0276, P0279 Or P0282

Possible causes are:
- Open circuit.
- Coil to coil short.
- FICM.
- Fuel injector.
Key off. Disconnect the suspect fuel injector. Visually inspect the suspect injector pins. See Figure. Measure the resistance between the suspect fuel injector pins, component side as follows:
- Terminals No. 1 and 2 - 0.7-1.5 ohms.
- Terminals No. 3 and 4 - 0.7-1.5 ohms.
- Terminals No. 1 and 3 - greater than 10,000 ohms.
- Terminals No. 1 and 4 - greater than 10,000 ohms.
- Terminals No. 2 and 3 - greater than 10,000 ohms.
- Terminals No. 2 and 4 - greater than 10,000 ohms.
Are the resistances within specifications? If yes, go to next step. If no, install a new fuel injector.

3) Check The Fuel Injector Circuits For An Open

Disconnect the FICM. Measure the resistance between the suspect fuel injector terminals No. 1, 2, 3 and 4, harness side and the FICM connector terminals, harness side. See CONTROL MODULE CONNECTOR IDENTIFICATION . Are the resistances less than 5.0 ohms? If yes, install a new FICM. If no, repair the circuit in question.

4) DTCs P0262, P0265, P0268, P0271, P0274, P0277, P0280 Or P0283

Possible causes are:
- Circuit short to voltage.
- Circuit short to ground.
Key off. Disconnect the suspect fuel injector to induce opposite DTC. Perform KOEO INJECTOR ELECTRICAL SELF-TEST under QUICK TEST. Is DTC P0261, P0264, P0267, P0270, P0273, P0276, P0279 or P0282 indicated? If yes, install a new fuel injector. If no, go to next step.

5) Check The Fuel Injector Circuits For A Short To Ground

Key off. Disconnect the FICM. Measure the resistance between the suspect injector terminals No. 1, 2, 3 and 4, harness side and ground. See Figure. Are the resistances greater than 10,000 ohms? If yes, go to next step. If no, repair the circuit in question.

6) Check The Fuel Injector Circuits For A Short To Voltage

Key on, engine off. Measure the voltage between the suspect injector terminals No. 1, 2, 3 and 4, harness side and ground. Is any voltage indicated? If yes, repair the circuit in question. If no, install a new FICM.

7) Check For Continuous Memory Fault DTCs

Check for continuous memory DTCs. Are DTCs P0301, P0302, P0303, P0304, P0305, P0306, P0307 or P0308 present? If yes, visually inspect for valve train, piston or any other base engine concerns. Repair as necessary. See appropriate article in ENGINES. If okay, see SYSTEM & COMPONENT TESTING - 6.0L DIESEL article to continue diagnostics. If no, go to next step.

8) Perform KOEO Self-Test & Injector Electrical Self-Test

Perform the KOEO ON-DEMAND SELF-TEST under QUICK TEST. Perform KOEO INJECTOR ELECTRICAL SELF-TEST under QUICK TEST. Are any DTCs present? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.

9) Check For KOER Codes

Perform the KOEO ON-DEMAND SELF-TEST under QUICK TEST. Are any DTCs present? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.

10) Check Fuel Supply Pressure

Check the fuel system pressure. See TEST 5: ELECTRIC FUEL PUMP PRESSURE in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. Is the fuel pressure within specification? If yes, go to next step. If no, repair as necessary.

11) Test For Fuel Aeration

Perform the Fuel Aeration Test. See TEST 12: FUEL AERATION TEST in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. Is the fuel aerated? If yes, repair as necessary. If no, go to next step.

12) Test For Oil Aeration

Perform the Oil Aeration Test. See TEST 18: OIL AERATION TEST in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. Is the oil aerated? If yes, change the oil and retest. If the oil is aerated, repair as necessary. See appropriate article in ENGINES. If no, go to next step.

13) Perform The Injector Enhanced Diagnostics

Perform Injector Interrupt for Enhanced Diagnostics. See SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. Is a weak cylinder identified? If yes, proceed as follows:
- If all four cylinders on one bank are identified, CHECK the following:
  1. Oil rail check valve for restriction.
  2. Fuel inlet check valve.
  3. FICM.
  4. Compression/head gaskets.
  5. Fuel contamination.
- If multiple or individual cylinders are identified, CHECK the following:
  1. Dual mass flywheel.
- If individual cylinders are identified, CHECK the following:
  1. Wiring to injector (should have already been seen with code).
  2. Injector hold-down bolt tightness.
  3. Injector copper gasket presence.
  4. Faulty injector.
- If the two rear cylinders are identified on either bank as weak, CHECK the following:
  1. AWA fitting in oil rail.
  2. Compression/head gasket.
- Any individual cylinder concern can be seen in the conditions listed above. If any two adjacent cylinders are identified as weak, CHECK the following:
  1. Compression/head gasket.
If no, go to next step.

14) Check Crankcase Pressure

Perform the Crankcase Pressure Test. See TEST 17: CRANKCASE PRESSURE TEST in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. Is the crankcase pressure above specification? If yes, repair as necessary. See appropriate article in ENGINES. If no, install a new PCM.

15) For DTCs P0263, P0266, P0269, P0272, P0275, P0278, P0281 Or P0284

Perform the Crankcase Pressure Test. See TEST 17: CRANKCASE PRESSURE TEST in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. Perform a cylinder compression test on the suspect cylinder. Are any concerns present? If yes, repair as necessary. See appropriate article in ENGINES. If no, go to next step.

16) DTCs P0263, P0266, P0269, P0272, P0275, P0278, P0281 Or P0284

Perform a visual inspection for the following mechanical concerns:
- Pushrods.
- Rocker arms.
- Valves.
- Valve springs.
Are any of the above concerns present? If yes, repair as necessary. See appropriate article in ENGINES. If no, inspect the fuel injector and O-rings. If the fuel injector and O-rings are okay, install a new fuel injector.