LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 158 (Engine Controls Self-Diagnostics - 2.2L) >> Diagnostic Tests >> DTC P0300: Engine Misfire Detected >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Pontiac Sunfire, 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
    2. NOTE: You MUST perform the Crankshaft Position (CKP) system variation learn procedure before proceeding with this diagnostic procedure. Go to CKP SYSTEM VARIATION LEARN PROCEDURE  under PROGRAMMING.
  2. Start the engine. Allow engine to idle or operate within the conditions listed in the Freeze Frame/Failure Records. Monitor all of the Misfire counters using the scan tool. Are any of the Misfire Current counters incrementing? If yes, go to next step. If no, go to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE - GASOLINE article.
  3. Are any other DTCs set? If yes, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.
  4. Can any abnormal engine noise be heard? If yes, diagnose engine mechanical problem. See appropriate article in ENGINES. If no, go to next step.
  5. Start and idle the engine. Compare the Manifold Absolute Pressure (MAP) voltage indicated by the scan tool with the typical scan data. Is the indicated value more than the typical value? If yes, go to DTC P0108: MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT - HIGH VOLTAGE . If no, go to next step.
  6. Inspect the following components:
    • The vacuum hoses and seals for splits, restrictions, and improper connections.
    • The crankcase ventilation system for vacuum leaks.
    • The PCM grounds for corrosion and loose connections.
    • The exhaust system for restrictions.
    • The fuel for contamination.

    Did you find and correct the condition? If yes, go to step  20. If no, go to next step.

    7. NOTE: Not grounding the IC module housing may cause an erratic spark.
  7. Turn ignition switch to OFF position. Remove the fuel pump relay. Remove the ignition coil housing assembly, keeping the Ignition Control Module (ICM) assembly connected to the harness connector. Connect a jumper wire between the top of the IC module and a good ground. Install the Ignition System Diagnosis Harness (J 36012-A), or equivalent. Install a Spark Tester (J 26792), or equivalent, on the No. 1 spark plug jumper wire. Ground the No. 4 spark plug jumper wire. The No. 4 wire is the companion to No. 1. Crank the engine with the remaining spark plug wires connected. Repeat the above steps by installing the spark tester on No. 4 and grounding No. 1. Do the same for the No. 2 and the No. 3 spark plugs. Ensure the companion wire is grounded. Does the spark tester spark on all cylinders? If yes, go to next step. If no, go to IGNITION SYSTEMS in SYSTEM & COMPONENT TESTS - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE article.
  8. Remove the spark plug from the cylinder that indicated a misfire. Inspect the spark plug. Does the spark plug appear to be OK? If yes, go to next step. If no, go to step  10.
  9. Exchange the suspected spark plug with another cylinder that is operating properly. Operate the vehicle under the same conditions that the misfire occurred. Did the misfire move with the spark plug? If yes, go to step  16. If no, go to step  13.
  10. Is the spark plug oil or coolant fouled? If yes, diagnose engine mechanical problem. See appropriate article in ENGINES. If no, go to next step.
  11. Is the spark plug gas fouled? If yes, go to step  14. If no, go to next step.
  12. Did the spark plug show any signs of being cracked, worn, or improperly gapped? If yes, go to step  14. If no, go to next step.
  13. Perform the fuel injector coil test. Go to FUEL INJECTOR COIL TEST under FUEL SYSTEMS in SYSTEM & COMPONENT TESTS - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE article. Did you find and correct the condition? If yes, go to step  17. If no, diagnose engine mechanical problem. See appropriate article in ENGINES.
  14. Perform the fuel system diagnosis. Go to FUEL SYSTEM DIAGNOSIS (GASOLINE) under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE article. Did you find and correct the condition? If yes, go to step  17. If no, diagnose engine mechanical problem. See appropriate article in ENGINES.
  15. Replace or gap the spark plug. After repair, go to step  17.
  16. Replace the faulty spark plug. After repair, go to step  17.
  17. Was the customer concern the MIL flashing? If yes, go to next step. If no, go to step  19.
  18. Operate the vehicle at 2500 RPM for 4 minutes. Operate the vehicle within the Conditions for Running the DTC P0420 as specified in the supporting text. See CONDITIONS FOR RUNNING DTC  in DTC P0420: TWC SYSTEM - LOW EFFICIENCY. Does the DTC run and pass? If yes, go to next step. If no go to DTC P0420: TWC SYSTEM - LOW EFFICIENCY .
  19. Using a scan tool, clear the DTCs. Turn ignition switch to OFF position for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC . You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? If yes, go to step  2. If no, go to next step.
  20. Using a scan tool, observe the CAPTURE INFO. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay at this time.
scientia non olet · About LEMON Manuals