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Home >> Nissan-Datsun >> 2003 >> Sentra Limited >> Repair and Diagnosis >> External Pages >> Different car >> Section 69 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0300: Multiple Cylinder Misfire Detected, PO301: Cylinder No. 1 Misfire Detected, PO302: Cylinder No. 2 Misfire Detected, PO303: Cylinder No. 3 Misfire Detected, PO304: Cylinder No. 4 Misfire Detected, PO305: Cylinder No. 5 Misfire Detected &/Or P0306: Cylinder No. 6 Misfire Detected >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Nissan Xterra and 2002 Nissan Frontier. However, it is still accessible from the selected car via links, so may be relevant.
  1. Start engine and let it idle. Check for intake leaks. Stop engine and visually inspect exhaust system, 3-way catalyst and muffler for blockage. If problem is found, repair as necessary. If problem is not found, go to next step.
  2. On 3.3L models, go to next step. On 2.4L models, check EGR function by performing appropriate DTC CONFIRMATION TEST under DTC P1402: EGR FUNCTION. If problem is found, repair as necessary. If problem is not found, go to next step.
  3. On all models, if using CONSULT-II, go to next step. If using generic scan tool, go to step  5 .
  4. Perform POWER BALANCE in ACTIVE TEST mode with CONSULT-II. If there is any cylinder which does not produce a momentary engine speed drop, go to step  7 . If all cylinders produce a momentary engine speed drop, go to step  6 .
  5. Start engine and let it idle. Individually, disconnect fuel injector harness connectors. If there is any cylinder which does not produce a momentary engine speed drop, go to step  7 . If all cylinders produce a momentary engine speed drop, go to next step.
  6. Listen to each fuel injector. If every injector clicks, go to next step. If any injector does not click, repair injector or circuit as necessary. See FUEL SYSTEM in SYSTEM & COMPONENT TESTING article.
  7. Turn ignition off. Disconnect spark plug wire from spark plug. Connect a known good spark plug. Place end of spark plug against a suitable ground and crank engine. If spark is detected, go to step  9 . If no spark is detected, go to next step.
  8. Inspect spark plug wires for cracks, damage, burned terminals and improper fit. Remove distributor cap. Measure resistance between spark plug end of each wire and corresponding distributor cap terminal. Resistance should be 4150-5610 ohms per foot at 77°F (25°C). If problem is found, repair as necessary. If problem is not found, check ignition coil, power transistor and their related circuits. See IGNITION SYSTEM in SYSTEM & COMPONENT TESTING article.
  9. Remove spark plugs. Inspect spark plugs for fouling or other damage. If problem is found, repair or replace spark plugs as necessary. If spark plugs are okay, go to next step.
  10. Check compression. See BASIC DIAGNOSTIC PROCEDURES article. See appropriate COMPRESSION SPECIFICATIONS table. If compression is as specified, go to next step. If compression is not as specified, check pistons, piston rings, valves, valve seats and cylinder head gaskets. Repair as necessary.
  11. Check fuel pressure. See BASIC DIAGNOSTIC PROCEDURES article. Fuel pressure should be about 34 psi (235 kPa) at idle. If fuel pressure is okay, go to next step. If fuel pressure is not okay, repair fuel system as necessary. See FUEL SYSTEM in SYSTEM & COMPONENT TESTING article.
  12. Perform BASIC INSPECTION. See ON-VEHICLE ADJUSTMENTS article. Adjust ignition timing, idle speed and throttle position switch as necessary. Go to next step.
  13. Start engine and warm to normal operating temperature. If using CONSULT-II, go to next step. If using generic scan tool, go to step  15 .
  14. Select MANU TRIG and HI SPEED in DATA MONITOR mode with CONSULT- II. Select HO2S1 (B1)/(B2) and HO2S1 MNTR (B1)/(B2). Hold engine speed at 2000 rpm under no load. Touch RECORD on CONSULT-II screen. The following should occur:
    • HO2S1 MNTR (B1)/(B2) in DATA MONITOR mode changes from RICH to LEAN to RICH 5 times in 10 seconds.
    • HO2S1 (B1)/(B2) voltage goes above 0.6V at least once.
    • HO2S1 (B1)/(B2) voltage goes below 0.3V at least once.
    • HO2S1 (B1)/(B2) voltage never exceeds 1.0V.

    If operation is as specified, go to step  16 . If operation is not as specified, replace appropriate HO2S1.

    15. CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  15. On 2.4L models, measure voltage between ground and ECM terminal No. 50 by backprobing. See Figure or Figure . See Figure . On 3.3L models, measure voltage between ground and ECM terminal No. 50 (bank 1) and No. 51 (bank 2) by backprobing. On all models, increase engine speed to 2000 RPM. On all models, the following should occur:
    • Voltage should cycle from less than .3 volt to more than .6 volt and back more than 5 times within 10 seconds.
    • Maximum voltage should be more than .6 volt at least once.
    • Minimum voltage should be less than .3 volt at least once.
    • Voltage should never exceed one volt.

    If operation is as specified, go to next step. If operation is not as specified, replace appropriate HO2S1.

  16. Select DATA MONITOR or MODE 1 with scan tool, and read Mass Airflow (MAF) signal. On 2.4L models, MAF reading should be 0.9-5.8 grams per second at idle and 7.5-13.2 grams per second at 2500 RPM. On 3.3L models, MAF reading should be 3.3-4.8 grams per second at idle and 12.0-14.9 grams per second at 2500 RPM. On all models, if MAF reading is as specified, go to step  18 . If MAF reading is not as specified, go to next step.
  17. Check connectors for rusted terminals or loose connections in MAF sensor circuit or engine grounds. See DTC P0101, DTC P0102 OR DTC P0103: MASS AIRFLOW SENSOR  . Repair as necessary.
  18. Check for possible causes of rough idle. See ROUGH IDLE under SYMPTOMS in TROUBLE SHOOTING - NO CODES article. If a problem is found, repair as necessary. If a problem is not found, go to next step.
  19. Some tests that were performed may cause a 1st trip DTC to set. Clear 1st trip DTC as necessary. Go to next step.
  20. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
COMPRESSION SPECIFICATIONS (2.4L)

Application psi (kPa) At 300 RPM
Standard 178 (1226)
Minimum 149 (1030)
Max. Difference Between Cylinders 14 (98)
COMPRESSION SPECIFICATIONS (3.3L)

Application psi (kPa) At 300 RPM
Standard 173 (1196)
Minimum 128 (883)
Max. Difference Between Cylinders 14 (98)
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