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Home >> Chrysler >> 2011 >> 300 C, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1312 (6.7L Diesel - DTCS P0008 To P0336 - 2500 Hd & 3500 Hd) >> DTC Troubleshooting >> P0300-Multiple-Cylinder-Misfire >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different car, the 2016 RAM 3500 HD and 2016 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
  1. LOW FUEL 
    1. Using the scan tool, verify that the fuel level is above 15%.

      Is the fuel level above 15%?

      Yes 

      • Go To  2

      No 

      • Add fuel.
      • Go To  2
  2. VEHICLE CONFIGURATION 

    Is the vehicle a pickup equipped with a 68RFE automatic transmission?

    Yes 

    • Vehicle is equipped with a 68RFE automatic transmission - Go To  12

    No 

    • Vehicle is equipped with a G56 Manual or AISIN automatic transmission - Go To  3
  3. CHECK FOR OTHER DTCS 
    1. Read the Freeze frame data.

      Is the DTC equal to the freeze frame DTC?

      Yes 

      • Go To  4

      No 

  4. CHECK FOR DAMAGED FUEL LINES 
    1. Visually inspect the injector supply lines for damage.

      Do you have any kinked or bent fuel lines?

      Yes 

      No 

      • Go To  5
  5. CHECK THE VALVE TRAIN 
    1. Visually inspect the valve train and check the valve lash on the suspect cylinders.

      Is the valve train functional and the lash within the specifications?

      Yes 

      • Go To  6

      No 

  6. CHECK FOR OBSTRUCTED FUEL INJECTOR SUPPLY 
    1. Remove the fuel injector supply lines for the suspect cylinders.
    2. Inspect both ends of the fuel injector supply lines for damage.
    3. Using shop air pressure, blow out the fuel injector supply lines to verify that they are not obstructed.

      Are the fuel lines free of debris or damage?

      Yes 

      • Go To  7

      No 

  7. CHECK FOR DAMAGED OR OBSTRUCTED HIGH PRESSURE CONNECTORS 
    1. Remove the high pressure connectors for the suspect cylinders.
    2. Inspect both ends of the high pressure connectors for signs of damage.
    3. Using shop air pressure, blow out the high pressure connectors to verify that they are not obstructed.

      Are the high pressure connectors free of debris or damage?

      Yes 

      • Go To  8

      No 

  8. CHECK THE FUEL INJECTOR AND VALVE COVER HARNESS TERMINALS 
    1. Turn the ignition off.
    2. Visually check the valve cover connectors, wiring, and fuel injector terminals for loose connections or damaged threads.
      NOTE:

      The valve cover gasket terminal nut to injector terminal torque should be 1.5 Nm (13 in-lbs).

      Are the connections, wiring, and terminals good?

      Yes 

      • Go To  9

      No 

  9. INTERNAL DAMAGED FUEL INJECTOR 
    1. With the scan tool, erase DTCs.
    2. Switch the misfiring injectors and high pressure connectors with injectors and high pressure connectors from cylinders that are firing properly.
    3. Idle the vehicle for a minimum of 2 minutes. If the coolant temperature is below 60°C (140° F), allow the engine to idle until the coolant temperature is above 60°C (140° F). The misfire monitor will not run if the coolant temperature is below 60°C (140° F).

      Did the misfire DTC follow the suspect injectors and high pressure connectors?

      Yes 

      No 

      • Go To  10
  10. CHECK FOR INTERNAL ENGINE DAMAGE 
    1. Perform engine compression test.

      Did the suspect cylinders pass the compression test?

      Yes 

      • Go To  11

      No 

  11. CHECK FOR INTERNAL ENGINE DAMAGE 
    1. Perform engine leak down test.

      Did the suspect cylinders pass the leak down test?

      Yes 

      • Test Complete.

      No 

  12. CHECK FOR OTHER DTCS (FOR VEHICLES EQUIPPED WITH 68RFE TRANSMISSIONS) 
    1. Ignition on, engine not running.
    2. Using the scan tool, read DTCs.
      NOTE:

      If P020A, P020B, P020C, P020D, P020E, or P020F are present, perform the Diagnostics for that DTC before continuing with this one.

      Are there any DTCs present for the EGR Valve, EGR Airflow Control Valve, Turbo, or the Exhaust Manifold Pressure (EMP) Sensor?

      Yes 

      No 

      • Go To  13
  13. CHECK THE EMP SENSOR, SENSOR TUBE, AND PRESSURE SENSING PORTS FOR DEBRIS 
    1. Remove the EMP Sensor from the pressure sensing port.
    2. Remove the EMP Sensor tube from the exhaust manifold.
    3. Inspect both the EMP Sensor and the sensor tube for debris. Also inspect the threaded port where the EMP sensor tube attaches to the exhaust manifold for debris.

      Were the EMP Sensor, EMP Sensor Tube, and the threaded sensor tube port in the exhaust manifold free of debris?

      Yes 

      • Go To  15

      No 

      • Remove the debris.
      • Go To  14
  14. CHECK FOR MISFIRE 
    1. Ignition on, engine not running.
    2. Using the scan tool, record and save the Freeze Frame data.
    3. Use the Freeze Frame report to determine the operating conditions under which the misfire DTC set. Pay particular attention to vehicle speed, engine speed, and throttle position.
    4. Using the scan tool, erase all DTCs.
    5. Turn the ignition off for 75 seconds.
    6. Operate the vehicle in the conditions determined from the Freeze Frame in sub-step 2. If Freeze Frame is unavailable, operate the vehicle in a variety of conditions - idle, steady state, and light to moderate throttle acceleration. Operate the vehicle for at least 10 minutes.
    7. Turn the ignition off for 75 seconds.
    8. Ignition on, engine not running.
    9. Using the scan tool, read DTCs.

      Did any misfire DTCs return as pending or active?

      Yes 

      • If any single cylinder misfire DTC set (P0301, P0302, P0303, P0304, P0305, P0306), perform the appropriate diagnostic tree for the cylinder(s) that set the DTCs.
      • If P0300 set by itself, Go To  15

      No 

  15. PERFORM THE FUEL SYSTEM RUN UP TEST 
    1. With the scan tool, navigate to System Tests and perform the Fuel System Run Up Test.
      NOTE:

      This test will take approximately 350 seconds to complete. The PCM will cut out each individual Fuel Injector three times and calculate the delta RPM change. Based on the delta RPM change, the test will indicate a bad cylinder based on the limits that have been set. When the test is complete, the engine will return to idle.

      NOTE:

      DTC P2201 will set while this test is running and can be disregarded. After the test has finished, this code can be cleared and should not be diagnosed.

      Do the results indicate that a cylinder is out of spec?

      Yes 

      • Go To  16

      No 

      • Go To  23
  16. CHECK FOR DAMAGED FUEL LINES 
    1. Visually inspect the injector supply lines (for the cylinder that failed the Fuel System Run Up test) for damage.

      Do you have any kinked or bent fuel lines?

      Yes 

      No 

      • Go To  17
  17. CHECK THE VALVE TRAIN 
    1. Visually inspect the valve train and check the valve lash on the suspect cylinders.

      Is the valve train functional and the lash within the specifications?

      Yes 

      • Go To  18

      No 

  18. CHECK FOR OBSTRUCTED FUEL INJECTOR SUPPLY 
    1. Remove the fuel injector supply lines for the suspect cylinders.
    2. Inspect both ends of the fuel injector supply lines for damage.
    3. Using shop air pressure, blow out the fuel injector supply lines to verify that they are not obstructed.

      Are the fuel lines free of debris or damage?

      Yes 

      • Go To  19

      No 

  19. CHECK FOR DAMAGED OR OBSTRUCTED HIGH PRESSURE CONNECTORS 
    1. Remove the high pressure connectors for the suspect cylinders.
    2. Inspect both ends of the high pressure connectors for signs of damage.
    3. Using shop air pressure, blow out the high pressure connectors to verify that they are not obstructed.

      Are the high pressure connectors free of debris or damage?

      Yes 

      • Go To  20

      No 

  20. CHECK THE FUEL INJECTOR AND VALVE COVER HARNESS TERMINALS 
    1. Turn the ignition off.
    2. Visually check the valve cover connectors, wiring, and fuel injector terminals for loose connections or damaged threads.
      NOTE:

      The valve cover gasket terminal nut to injector terminal torque should be 1.5 Nm (13 in-lbs).

      Are the connections, wiring, and terminals good?

      Yes 

      • Go To  21

      No 

  21. CHECK FOR INTERNAL ENGINE DAMAGE 
    1. Perform engine compression test.

      Did the suspect cylinders pass the compression test?

      Yes 

      • Go To  22

      No 

  22. CHECK FOR INTERNAL ENGINE DAMAGE 
    1. Perform engine leak down test.

      Did the suspect cylinders pass the leak down test?

      Yes 

      • Replace the fuel injector(s) and high pressure connector(s) for the suspect cylinders.
      • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .

      No 

  23. CHECKING FUEL QUALITY/CONTAMINATION 
    1. Check the quality of the fuel using the DIESEL FUEL CONTAMINATION TEST PROCEDURE. Refer to DIESEL FUEL CONTAMINATION TESTING PROCEDURE .

      Was any contamination detected?

      Yes 

      • Perform the appropriate repair according to the testing and cleaning procedure.
      • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .

      No 

      • Go To  24
  24. INJECTOR RETURN FLOW TEST 
    1. Perform the Injector Return Flow test. Refer to INJECTOR RETURN FLOW TEST .

      Does the injector drainage meet the test specification?

      Yes 

      • Go To  25

      No 

  25. CHECK THE ENGINE PRESSURE SENSORS 
    1. Turn the engine off, ignition on.
    2. Using the scan tool, compare the Barometric Pressure Sensor and the Exhaust Pressure Sensor reading.

      Are the two readings equal?

      Yes 

      • Go To  26

      No 

      • Compare the two readings to the Inlet Air Pressure Sensor reading. Replace the sensor that does not match the Inlet Air Pressure Sensor.
      • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
  26. CHECK CRANKCASE FILTER 
    1. Verify proper Crankcase Filter operation.

      Were any problems found?

      Yes 

      No 

      • Go To  27
  27. CHECKING THE INTAKE SYSTEM 
    1. Check for inlet restriction, inspect air filter for excessive dirt/debris. Verify air intake lines are not kinked or restricted.
    2. Refer to INTAKE AIR SYSTEM PRESSURE TEST and perform the CHECKING THE INTAKE AIR SYSTEM PRESSURE diagnostic procedure.
    3. Inspect Turbocharger for wheel clearance and proper wastegate operation.

      Were any problems found?

      Yes 

      • Repair as necessary. Inspect and clean any soot fouling in the Air Handling and Exhaust systems as needed.
      • Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .

      No 

      • Go To  28
  28. CHECKING THE EGR SYSTEM 
    1. Perform the following EGR system checks:
      • Look for visible signs (soot streaks) of an external EGR system leak.
      • Remove the EGR Outlet Temperature Sensor from the thermostat outlet. Check the outlet for blockage or debris.
      • Remove EGR Crossover Tube from EGR Cooler and EGR Valve. Inspect the tube for a restriction.
      • Verify EGR Cooler is not leaking. Check for coolant in EGR plumbing, engine overheat fault codes, and low coolant level.
      • Check the Air Intake Grid Heater for excessive soot build up or restriction.

      Were any problems found?

      Yes 

      • If the soot inside the EGR Crossover Tube is oily, inspect the Turbocharger for leaking oil into the intake system. If Turbo is leaking, replace the Turbo. If Turbo is not leaking, clean the Crossover Tube, remove and clean the EGR Valve and EGR Cooler. Also, inspect the valve guide seals for wear or leakage.
      • Go To  29

      No 

      • Go To  29
  29. CHECK THE EXHAUST AFTERTREATMENT SYSTEM FOR A RESTRICTION 
    1. Perform the AFTERTREATMENT INSPECTION GUIDELINE procedure. Refer to AFTERTREATMENT INSPECTION GUIDELINE .

      Were any problems found during the inspection?

      Yes 

      No