LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different car >> Section 114 (Engine Controls And Fuel - 4.3L (LV1) - Diagnostic Information And Procedures (1 Of 2)) >> Diagnostic Information and Procedures >> DTC P0300-P0306 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
  1. Verify the following conditions do not exist:
    • If a condition exists 

      Repair or replace as necessary.

    • Go to next step: If no conditions exist 
  2. Ignition/Vehicle - Off
  3. Disconnect the appropriate component: Spark Plug Wire @ Spark Plug
  4. Verify a condition does not exist with the component: Spark Plug Boot - Carbon Tracking/Fluid intrusion/Visible Damage
    • If a condition exists 

      Repair or replace as necessary.

    • Go to next step: If no condition exists 
  5. Install J-26792 Ignition Spark Tester @ Spark Plug Wire & Ground
  6. Engine - Running
    7. NOTE:

    An erratic or weak spark is considered a no spark condition.

  7. Verify there is spark at the tool.
    • If there is no spark 
    1. Remove the appropriate component: Spark Plug Wire
    2. Test for 1, 850 to 2, 250 ohms between the test points: Each terminal of the component
    • Go to next step: If there is spark 
  8. Ignition/Vehicle - Off
  9. Remove the appropriate component: Spark Plug
  10. Verify the component specifications are correct: Spark Plug - Gap / Heat Range /Torque Refer to: Ignition System Specifications
    • If a condition exists 

      Repair or replace as necessary.

    • Go to next step: If no condition exists 
  11. Verify a condition does not exist with the component: Spark Plug - Carbon Tracking/Fouled/Visible Damage
    • If a condition exists 

      Repair or replace as necessary.

    • Go to next step: If no condition exists 
  12. Swap the two components: Spark Plug - The original component that set the DTC & Another known good component from the vehicle
  13. Engine - Running
  14. Verify the scan tool parameter: Cylinder 1 - 6 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 
  15. Perform the following procedure/test: Fuel Injector Balance - Refer to: Fuel System 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 
  16. 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 
  17. All OK.
scientia non olet · About LEMON Manuals