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Home >> Chevrolet >> 2001 >> Tracker 2D Utility, 4WD, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics >> Diagnostic Tests >> DTC P0300: Engine Misfire Detected >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check, go to next step.
  2. Start engine and observe for a misfire at idle. If a misfire is present, go to step  4 . If a misfire is not present, go to next step.
  3. Turn ignition on, with engine off. Using scan tool, clear DTCs. Operate vehicle within FREEZE FRAME conditions. Retrieve DTCs. If this DTC resets, go to next step. If this DTC does not reset, see DIAGNOSTIC AIDS  .
  4. Turn ignition off. Visually and physically check the following items:
    • Improperly operating or leaking PCV valve.
    • Incorrect PCV valve.
    • Vacuum leak at intake manifold or gasket.
    • Vacuum leak at a cracked, split or worn vacuum hose.

    Repair as necessary. After repairs, go to step  18 . If no problem(s) exists, go to next step.

  5. Disconnect fuel injector harness connectors. Remove No. 1 ignition coil. Install a spark tester to No. 1 ignition coil spark plug boot. Crank engine while observing spark tester. Repeat procedure on all ignition coils. If any ignition coil indicates a weak spark, go to next step. If spark is okay on all ignition coils, go to step  9 .
  6. Check ignition coils and spark plug wires for cracks, terminal corrosion, carbon tracking and moisture. Repair as necessary. After repairs, go to step  18 . If ignition coils and spark plug wires are okay, go to next step.
  7. Turn ignition off. Swap ignition coils. Replace the suspected faulty ignition coil with a functioning ignition coil. Install Spark Tester (J-26792) and test for spark, as performed in step  4 . If test indicates a crisp Blue spark while cranking engine, go to next step. If test does not indicate a crisp Blue spark while cranking engine, diagnose Electronic Ignition (EI) system. See NO START DIAGNOSIS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  8. Replace the faulty ignition coil. After replacing ignition coil, go to step  18 . If no problem is found, go to next step.
  9. Remove spark plugs. Visually and physically inspect each spark plugs for correct performance and condition. Replace as necessary. After replacing spark plugs, go to step  12 . If spark plugs were okay, go to next step.
  10. Turn ignition off. Disconnect fuel injector harness connectors. Install Injector Test Light (J-34730-2B) into each of the fuel injector harness connectors one at time. Observe injector test light for each injector while cranking engine. If injector test light flashes for each fuel injector while cranking engine, go to next step. If injector test light does not flash for each fuel injector while cranking engine, diagnose fuel injector circuit. See FUEL SYSTEM in appropriate SYSTEM & COMPONENT TESTING article.
  11. Check fuel injectors for proper operation. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEM in appropriate SYSTEM & COMPONENT TESTING article. If a faulty fuel injector is found and replaced, go to step  18 . If no problem is found, go to step  14 .
  12. If a spark plug was replaced due to rich fueling condition or wet fuel fouling, see BASIC FUEL SYSTEM CHECKS (GASOLINE) in appropriate BASIC DIAGNOSTIC PROCEDURES article. If sparks plugs were okay, go to next step.
  13. If a spark plug is replaced because of fuel, oil or coolant fouling, go to step  15 . If a spark plug is not replaced because of fuel, oil or coolant fouling, go to step  18 .
  14. Check EGR valve for excessive flow or sticking open. Repair as necessary. After repairs, go to step  18 . If EGR valve is okay, go to next step.
  15. Check engine for the following mechanical problems:
    • Worn or faulty camshaft.
    • Leaky or sticky valves.
    • Excessive valve deposits.
    • Broken or leaky piston rings.
    • Weak valve springs.
    • Incorrect valve timing.
    • Intake (vacuum) leaks.
    • Leaking head gasket.
    • Loose or broken motor mounts.

    Repair as necessary. After repairs, go to step  18 . If no problem exists, go to next step.

  16. Remove CMP sensor (sensor is located on rear of cylinder head). Check CMP sensor for damage, foreign material on sensor (magnet) surface, and water or corrosion at connector terminals. Repair as necessary. After repairs, go to step  18 . If CMP sensor is okay, go to next step.
  17. Check CMP sensor signal rotor in CMP sensor housing for damaged teeth, foreign material, and correct installation. Repair as necessary. After repairs, go to step  18 . If CMP sensor signal rotor is okay, see DIAGNOSTIC AIDS  .
  18. Turn ignition on, with engine off. Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Start engine and operate vehicle within the conditions for running the DTC or until this DTC test has run. See CODE ENABLE CRITERIA  . If DTC runs and passes, go to next step. If DTC resets, go to step  2 .
  19. Turn ignition on, with engine off. Using scan tool, observe the stored information and Capture Info. If scan tool displays any undiagnosed DTCs, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  . If no DTCs are displayed, system is okay.
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