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Home >> Chevrolet >> 2018 >> Suburban 3500 HD LT >> Repair and Diagnosis >> External Pages >> Different car >> Section 2 (Engine Controls And Fuel - 5.3L (L83) Or 6.2L (L86) - DTC P0010 To DTC P0442) >> Diagnostic Information And Procedures >> DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308: Misfire Detected >> Circuit/System Testing

Circuit/System Testing

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  1. Verify the following conditions do not exist :
    • Engine - Vacuum leak
    • Exhaust System - Leaking/Missing components/Restricted - Refer to Symptoms - Engine Exhaust
    • Fuel - Contaminated/Dirty/Fill Level = Low - Refer to Alcohol/Contaminants-in-Fuel Diagnosis
    • Fuel Pressure - High/Low - Refer to Fuel System Diagnosis
    • Positive Crankcase Ventilation System - Leaking/Incorrect connection/Restricted
    • Spark Plug Boot - Carbon Tracking/ Fluid intrusion/Visible Damage
    • Spark Plug - Carbon Tracking/Fouled/Visible Damage
    • Vacuum Hoses - Kinked/Leaking/Incorrect connection/Restricted
    • If a condition exists 

      Repair or replace as necessary.

    • Go to next step : If no conditions exist 
  2. Ignition/Vehicle - Off
  3. Disconnect the component : Spark Plug Wire@Spark Plug
  4. Install the special tool : J-26792  Ignition Spark Tester @ Spark Plug Wire & Ground
  5. Engine - Running
  6. Verify there is spark at the special tool.
    NOTE: An erratic or weak spark is considered a no spark condition.
    • If there is no spark 
    1. Remove the appropriate component : Spark Plug Wire
    2. Test for 1, 850 to 2, 250 Ω between the test points : Each terminal of the component
    • Go to next step : If there is spark 
  7. Ignition/Vehicle - Off
  8. Verify the component specifications are correct : Spark Plug - Gap / Heat Range /Torque
    • If not correct 

      Repair or replace as necessary.

    • Go to next step : If correct 
  9. Swap the two components : Spark Plug - The original component that set the DTC & Another known good component from the vehicle
  10. Engine - Running
  11. Verify the scan tool parameter : Cylinder 1-8 Current Misfire Counter = Increments - At the original component location the DTC set.
    • If the parameter value does not increment 

      Replace the component : Spark Plug - The original component that set the DTC

    • Go to next step : If the parameter value increments 
  12. Perform the following procedure/test : Fuel Injector Balance - Refer to Fuel Injector Diagnosis

    Verify the procedure/test passes.

    • If the procedure/test does not pass 

      Replace the component that failed the test : Q17 Fuel Injector

    • Go to next step : If the procedure/test passes 
  13. Verify the condition does not exist : An engine mechanical condition. Refer to Symptoms - Engine Mechanical
    • If a condition exists 

      Repair or replace as necessary.

    • Go to next step : If no condition exists 
  14. All OK.
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