LEMON Manuals: Even more car manuals for everyone
Home >> Dodge and Ram >> 2015 >> Durango SXT, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 189 (3.6L - DTCS P0138 To P0456) >> DTC Troubleshooting >> P0301-Cylinder 1 Misfire >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different car, the 2016 Dodge Durango. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK FOR AN ACTIVE DTC 
    1. Diagnose and repair any other active component or circuit DTCs before continuing with this procedure.
    2. Turn the ignition on.
    3. With the scan tool, read DTCs and record on the repair order. Copy DTC and Freeze Frame information.
    4. With the scan tool, erase DTCs.
      WARNING:

      When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.

    5. Start the engine and operate the vehicle under conditions similar to which the DTC was set.
    6. With the scan tool, view the Misfire Monitor to see which cylinders are effected.
      NOTE:

      It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set.

    7. With the scan tool, read DTCs and record on the repair order.

      Is the DTC active or pending?

      Yes 

      • Go To  2

      No 

  2. VISUAL INSPECTION 
    NOTE:

    Anything that affects the speed of the crankshaft can cause a misfire DTC.

    NOTE:

    When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit.

    NOTE:

    Misfire may occur and may not be caused by component failure. Misfires detected during a deceleration are indicators of mechanical concerns.

    1. Visually inspect the engine for any of the following conditions:
      • Worn serpentine belt. Refer to BELT, SERPENTINE, DIAGNOSIS AND TESTING .
      • Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump.
      • Misalignment of water pump, P/S Pump or A/C Compressor pulleys.
      • Corroded PCM power or ground circuits.
      • Improper CKP, CMP, MAP, or Throttle Position Sensor mounting.
      • Poor connector/terminal to component connection for CKP Sensor, CMP Sensor, MAP Sensor, TP Sensor, Fuel Injector, Ignition Coil, etc.
      • Vacuum leaks.
      • Restricted Exhaust system. Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS diagnostic procedure. Refer to CHECKING THE EXHAUST SYSTEM FOR LEAKS .
      • Restricted Air Induction system.
      • Internal engine component malfunction.
      • Moisture on ignition system components.
      • Insufficient fuel.
      • Low quality fuel.

      Were any problems found?

      Yes 

      No 

      • Go To  3
  3. CHECKING THE OXYGEN SENSOR OPERATION 
    1. Perform the diagnostic procedure for CHECKING THE OXYGEN SENSOR OPERATION. Refer to CHECKING THE OXYGEN SENSOR PERFORMANCE .

      Were any problems found?

      Yes 

      • Repair as necessary in accordance with the Service Information.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK FOR A FUEL OR IGNITION SYSTEM PROBLEM 
    1. Start the engine and allow it to idle long enough for the O2 Sensor to warm up and go into closed loop operation. This may take a couple of minutes.
    2. With the scan tool, observe the voltage reading of the Downstream O2 Sensor.
      NOTE:

      If the misfire is caused by a lack of fuel condition, the O2 Sensor voltage will tend to stay at the low end of the range (approximately 2.5 volts). If the misfire is caused by a lack of or poor quality spark condition, the O2 Sensor voltage will tend to stay at the high end of the voltage range (approximately 3.5 volts).

      Does the Downstream O2 Sensor voltage reading tend to be staying at the low end (2.5 volts) or high end (3.5 volts) of the voltage range?

      High end of the range (3.5 volts) 

      • Go To  5

      Low end of the range (2.5 volts) 

      • Go To  7
  5. IGNITION SYSTEM OPERATION 
    WARNING:

    When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.

    NOTE:

    When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. It may be necessary to erase the DTC or reset the misfire monitor before proceeding with this step in order for the PCM to fire the Ignition Coil.

    1. Perform the CHECKING THE IGNITION COIL OPERATION test procedure on the Ignition Coil of the cylinder that is misfiring. For Multiple Cylinder Misfire, check each Ignition Coil individually. Refer to CHECKING THE IGNITION COIL PERFORMANCE .

      Were any problems found?

      Yes 

      • Repair as necessary in accordance with the Service Information.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  6
        NOTE:

        Reconnect the Fuel Injector harness connector before continuing.

  6. SPARK PLUG 
    1. Turn the ignition off.
    2. Exchange the Spark Plug with a known good cylinder that was not indicating a misfire.
    3. Start the engine and monitor the misfire monitor screen.

      Did the misfire switch to the previously good cylinder?

      Yes 

      No 

      • Go To  11
  7. CHECKING THE FUEL DELIVERY SYSTEM 
    1. Perform the CHECKING THE FUEL DELIVERY SYSTEM test procedure. Refer to CHECKING THE FUEL DELIVERY SYSTEM (HARD START) .

      Were any problems found?

      Yes 

      • Repair as necessary in accordance with the Service Information.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  8
  8. FUEL INJECTOR CONTROL 
    1. Turn the ignition off.
    2. Disconnect the Fuel Injector harness connector of the misfiring cylinder. For Multiple Cylinder Misfire, check each Fuel Injector individually.
    3. Turn the ignition on.
      NOTE:

      When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinder's Injector Control circuit. It may be necessary to erase the DTC or reset the misfire monitor before proceeding with this step in order for the PCM to fire the Fuel Injector.

    4. Install an Injector Noid light.
    5. With the scan tool, actuate the Fuel Injector.

      Does the Noid light blink/flicker during the actuation?

      Yes 

      No 

      • Go To  9
  9. CHECK THE INJECTOR CONTROL CIRCUIT FOR A SHORT TO GROUND 
    1. Turn the ignition off.
    2. Remove the Injector Noid light.
    3. Disconnect the PCM C2 harness connector.
    4. Check for continuity between ground and the Injector Control circuit at the Fuel Injector harness connector of the misfiring cylinder.

      Is there continuity between ground and the Injector Control circuit?

      Yes 

      • Go To  10

      No 

      • Repair the Injector Control circuit for a short to ground.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  10. CHECK THE INJECTOR CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    CAUTION:

    Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.

    1. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
    2. Measure the resistance of the Injector Control circuit between the Fuel Injector harness connector of the misfiring cylinder and the GPEC Adaptor.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  11

      No 

      • Repair the Injector Control circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  11. CHECKING THE MAP SENSOR OPERATION 
    1. Perform the diagnostic procedure for CHECKING THE MAP SENSOR OPERATION. Refer to CHECKING THE MAP SENSOR PERFORMANCE .

      Were any problems found?

      Yes 

      • Repair as necessary in accordance with the Service Information.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  12
  12. CHECKING THE ENGINE MECHANICAL SYSTEM 
    1. Perform the diagnostic procedure for CHECKING THE ENGINE MECHANICAL SYSTEM. Refer to DIAGNOSIS AND TESTING .

      Were any problems found?

      Yes 

      • Repair as necessary in accordance with the Service Information.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  13
  13. CHECK RELATED PCM AND COMPONENT CONNECTIONS 
    1. Perform any Service Bulletins that apply.
    2. Disconnect all PCM harness connectors.
    3. Disconnect all related in-line harness connections (if equipped).
    4. Disconnect the related component harness connectors.
    5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Check for spread terminals and verify proper terminal tension.

      Repair any conditions that are found.

    6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    9. With the scan tool, erase DTCs.
    10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    11. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      No 

scientia non olet · About LEMON Manuals