Test P: Misfire/Injector Driver Circuit Operation
PINPOINT TEST P: MISFIRE/INJECTOR DRIVER CIRCUIT OPERATIONFlow Chart (Part 1):
Flow Chart (Part 2):
NOTE: Inspect the fuel injector control module (FICM) harness for damage, chafing and correct routing within the engine compartment and around engine components.
This pinpoint test is intended to diagnose the following:
- fuel injector
- harness circuits: fuel injector close coil, power and ground and fuel injector open coil, power and ground
- FICM (12B559)
- powertrain control module (PCM)
FICM-A Connector
FICM-A Connector:
FICM-B Connector
FICM-B Connector:
Fuel Injector Connector
Fuel Injector Connector:
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P1 : PRELIMINARY DIAGNOSIS
NOTE: Diagnostic trouble codes (DTCs) P0261, P0264, P0267, P0270, P0273, P0276, P0279 and P0282 may be retrieved due to FICM low voltage concerns. Diagnose P0261, P0264, P0267, P0270, P0273, P0276, P0279 and P0282 first, if all 8 are retrieved together.
- Carry out a visual inspection.
- Confirm sufficient clean fuel.
- Confirm engine oil quality and level.
- Retrieve and record any continuous and on-demand DTCs
- Record the freeze frame data
- Clear the DTCs.
- Carry out the KOEO self-test. Quick Test Description
- Carry out the injector electrical self-test. Quick Test Description
- Carry out the KOER self-test. Quick Test Description
- Are any DTCs retrieved?
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P2 : DIAGNOSTIC TROUBLE CODES (DTCS) P0261, P0264, P0267, P0270, P0273, P0276, P0279, OR P0282
NOTE:
- Disconnect the suspect fuel injector harness connector. Only the suspect injector needs to be diagnosed.
- Fuel injectors must be tested at normal operating temperature and after a cold soak at ambient temperature to complete this step.
- Refer to the injector coil resistance tables for resistance values.
- Ignition OFF.
- Fuel Injector connector disconnected.
- Visually inspect the suspect injector pins.
- Measure the resistance between:
INJECTOR COIL RESISTANCE
Injector Coil Resistance:
- Allow the vehicle temperature to stabilize at the ambient temperature. Verify no accessories are in use (engine block or oil heaters).
- Measure the resistance between:
INJECTOR COIL RESISTANCE
Injector Coil Resistance:
- Is the resistance within specification?
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P3 : CHECK FOR SHORTS IN THE INJECTOR
- Measure the resistance between:
- Are the resistances greater than 10 kOhm?
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P4 : CHECK THE FUEL INJECTOR CIRCUITS FOR AN OPEN
- Suspect FICM connector disconnected.
- Measure the resistance between:
- Are the resistances less than 5 Ohm?
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P5 : DIAGNOSTIC TROUBLE CODES (DTCS) P0262, P0265, P0268, P0271, P0274, P0277, P0280, OR P0283
NOTE: Disconnect the suspect fuel injector harness connector. Only the suspect injector needs to be diagnosed.
- Ignition OFF.
- Fuel Injector connector disconnected.
- Suspect FICM connector disconnected.
- Measure the resistance between:
- Are the resistances greater than 10 kOhm?
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P6 : CHECK THE FUEL INJECTOR CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between:
- Are the resistances greater than 10 kOhm?
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P7 : CHECK THE FUEL INJECTOR CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- Measure the voltage between:
- Check for continuous memory DTCs.
- Is any voltage present?
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P8 : CHECK FOR CONTINUOUS MEMORY DTCS
- Check for continuous memory DTCs.
- Are DTCs P0301, P0302, P0303, P0304, P0305, P0306, P0307, or P0308 present?
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P9 : DIAGNOSTIC TROUBLE CODES (DTCS) P0263, P0266, P0269, P0272, P0275, P0278, P0281, OR P0284
NOTE: Do not replace the fuel injectors based only on the results of the power balance test. Always verify the fuel delivery system, the high pressure oil system, the fuel injector electrical system, and the base engine system functions are operating correctly.
- Carry out the Power Balance Test. Refer to Performance Diagnostic Procedures 6b. Power Balance Test Component Tests and General Diagnostics
- Record which cylinders are low on the Power Balance test.
- Is a weak cylinder identified?
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P10 : 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?
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P11 : CHECK THE FUEL SUPPLY PRESSURE
- Carry out a visual inspection. Check for fuel leaks in the engine compartment. Repair as necessary.
- Carry out the Fuel System Delivery Test. Refer to Performance Diagnostic Procedures 10a. Fuel System Delivery Component Tests and General Diagnostics
- Is the fuel pressure within specification?
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P12 : CHECK FOR FUEL AERATION
- Carry out the Fuel Aeration Test. Refer to Performance Diagnostic Procedures. 10c. Fuel Aeration Test Component Tests and General Diagnostics
- Is the fuel aerated?
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P13 : CHECK FOR COMBUSTION GAS IN THE FUEL RAIL
- Carry out the Combustion Gas in the Fuel Rail Test - Bubble Test. Refer to Performance Diagnostic Procedures. 16a. Combustion Gas In The Fuel Rail Test - Bubble Test Component Tests and General Diagnostics
- Is combustion gas in the fuel rail indicated?
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P14 : CHECK THE VOLTAGE SUPPLIED TO THE INJECTORS
- Carry out the Check FICM M Voltage to Actuate Injectors Test. Refer to Hard Start or No Start Diagnostic Procedures 10c. Check FICM M Voltage to Actuate Injectors Hard Start or No Start Diagnostic Procedures
- Is sufficient voltage supplied to the injectors?
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P15 : CHECK THE ICP SENSOR SIGNAL
- Carry out the Low Idle Stability Test. Refer to Performance Diagnostic Procedures. 12a. Low Idle Stability (ICP Pressure) Component Tests and General Diagnostics
- Is the ICP signal operating correctly?
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P16 : CHECK THE HIGH PRESSURE OIL SYSTEM IPR RESPONSE
- Carry out the Injection Pressure Regulator (IPR) Test. Refer to Performance Diagnostic Procedures 12b. Injection Pressure Regulator Test Component Tests and General Diagnostics
- Is the IPR responding correctly?
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P17 : CHECK FOR OIL AERATION
- Carry out the Oil Aeration Test. Refer to Performance Diagnostic Procedures. 15. Oil Aeration Test Component Tests and General Diagnostics
- Is the oil aerated?
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P18 : CHECK THE CRANKCASE PRESSURE
- Carry out the Crankcase Pressure Test. Refer to Performance Diagnostic Procedures. 14. Crankcase Pressure Test Component Tests and General Diagnostics
- Carry out a cylinder compression test on the suspect cylinder.
- Are any concerns present?
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P19 : POWER BALANCE TEST CHECK
- Carry out the Power Balance Test. Refer to Performance Diagnostic Procedures 6b. Power Balance Test Component Tests and General Diagnostics
- Is a weak cylinder identified?
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P20 : CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
- Is the concern still present?
