Home ReviewsRefund
Home/Infiniti/M45/Infiniti M45 II (2002-2004)/Repair manual/Testing & Diagnostics/Engine Controls - Trouble Shooting - No Codes: Other
Contents Wiring diagrams Section: Testing & Diagnostics All sections

Engine Controls - Trouble Shooting - No Codes: Other Infiniti M45 II

Testing & Diagnostics ~1408 words

HARD START OR NO START (CRANKS NORMALLY)

Note. Unless otherwise indicated, see SYSTEM & COMPONENT TESTING article for testing procedures.

  1. Check fuel pump circuit.
  2. Check fuel pressure regulator system.
  3. Check fuel injector circuits.
  4. Check evaporative emission system.
  5. Check electric throttle control actuator (Except QX4).
  6. Check positive crankcase ventilation system.
  7. Check incorrect idle speed adjustment.
  8. Check ignition circuit.
  9. Check incorrect ignition timing adjustment.
  10. Check main power supply and ground circuit.
  11. Check air conditioner circuit.
  12. Check mass airflow sensor circuit.
  13. Check engine coolant temperature sensor circuit.
  14. Check Idle Air Control Valve-Auxiliary Air Control (IACV-AAC) valve circuit (QX4 only).
  15. Check crankshaft position sensor (POS) circuit.
  16. Check camshaft position sensor circuit.
  17. Check ECM.
  18. Check start signal circuit (Except FX35/FX45).
  19. Check intake valve timing control solenoid valve circuit (M45 & Q45 only).

ENGINE STALLS

Note. Unless otherwise indicated, see SYSTEM & COMPONENT TESTING article for testing procedures.

  1. Check fuel pump circuit.
  2. Check fuel injector circuits.
  3. Check Idle Air Control Valve-Auxiliary Air Control (IACV-AAC) valve circuit (QX4 only).
  4. Check electric throttle control actuator (Except QX4 only).
  5. Check ignition circuit.
  6. Check main power supply and ground circuit.
  7. Check mass airflow sensor circuit.
  8. Check front heated oxygen sensor circuit.
  9. Check engine coolant temperature sensor circuit.
  10. Check TP sensor circuit.
  11. Check throttle position sensor adjustment (Only QX4).
  12. Check ECM power and ground circuits.
  13. Check crankshaft position sensor (POS) circuit.
  14. Check camshaft position sensor circuit (Except QX4).
  15. Check vehicle speed sensor circuit.
  16. Check power steering pressure sensor circuit.
  17. Check refrigerant pressure sensor circuit (Except I35 & QX4).
  18. Check fuel pressure regulator. See «BASIC DIAGNOSTIC PROCEDURES»(ref-151802) article.
  19. Check EVAP system.
  20. Check PCV system.
  21. Check ignition timing and idle speed adjustment. See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  22. Check fuel delivery system.
  23. Check intake valve timing control solenoid valve circuit (Except I35 & QX4).
  24. Check A/C circuit.

HESITATION OR SURGE

Note. Unless otherwise indicated, see SYSTEM & COMPONENT TESTING article for testing procedures.

  1. Check ignition timing adjustment. See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  2. Check fuel pump circuit.
  3. Check fuel injector circuits.
  4. Check electric throttle control actuator (Except QX4).
  5. Check ignition circuit.
  6. Check mass airflow sensor circuit.
  7. Check front HO2S circuit.
  8. Check engine coolant temperature sensor circuit.
  9. Check TP sensor circuit.
  10. Check knock sensor circuit.
  11. Check intake valve timing control solenoid valve circuit (Except I35 & QX4).
  12. Check ECM.
  13. Check A/C circuit.
  14. Check vehicle speed sensor circuit.
  15. Check park/neutral position switch circuit.
  16. Check accelerator pedal position sensor circuit (Except QX4).
  17. Check TP sensor adjustment (QX4 only). See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  18. Check Idle Air Control Valve-Auxiliary Air Control (IACV-AAC) valve circuit (QX4 only).
  19. Check fuel pressure regulator. See «BASIC DIAGNOSTIC PROCEDURES»(ref-151802) article.
  20. Check EVAP system.
  21. Check PCV system.
  22. Check main power supply and ground circuit.
  23. Check VDC/TCS/ABS control unit (Except QX4).

SPARK KNOCK/DETONATION

Note. Unless otherwise indicated, see SYSTEM & COMPONENT TESTING article for testing procedures.

  1. Check ignition timing adjustment. See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  2. Check ignition circuit.
  3. Check mass airflow sensor circuit.
  4. Check accelerator pedal position sensor circuit (Except QX4).
  5. Check fuel pump circuit.
  6. Check fuel injector circuits.
  7. Check electric throttle control actuator (Except QX4).
  8. Check ECM power and ground circuits.
  9. Check A/C circuit.
  10. Check front HO2S circuit.
  11. Check engine coolant temperature sensor circuit.
  12. Check for faulty ECM. See appropriate SELF-DIAGNOSTICS article.
  13. Check fuel pressure regulator. See «BASIC DIAGNOSTIC PROCEDURES»(ref-151802) article.
  14. Check EVAP system.
  15. Check PCV system.
  16. Check Idle Air Control Valve-Auxiliary Air Control (IACV-AAC) valve circuit (QX4 only).

LACK OF POWER/POOR ACCELERATION

Note. Unless otherwise indicated, see SYSTEM & COMPONENT TESTING article for testing procedures.

  1. Check ignition timing. See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  2. Check accelerator pedal position sensor circuit (Except QX4).
  3. Check intake valve timing control solenoid valve circuit (Except I35 & QX4).
  4. Check fuel pump circuit.
  5. Check fuel injector circuits.
  6. Check ignition circuits.
  7. Check mass airflow sensor circuit.
  8. Check front HO2S circuit.
  9. Check engine coolant temperature sensor circuit.
  10. Check TP sensor circuit.
  11. Check electric throttle control system (Except QX4).
  12. Check throttle position sensor adjustment (Only QX4).
  13. Check ECM power and ground circuits.
  14. Check A/C circuit.
  15. Check vehicle speed sensor circuit.
  16. Check for faulty ECM. See appropriate SELF-DIAGNOSTICS article.
  17. Check park/neutral position switch circuit (Only I35 & QX4).
  18. Check fuel pressure regulator. See «BASIC DIAGNOSTIC PROCEDURES»(ref-151802) article.
  19. Check EVAP system.
  20. Check PCV system.
  21. Check Idle Air Control Valve-Auxiliary Air Control (IACV-AAC) valve circuit (QX4 only).
  22. Check TP sensor adjustment (QX4 only). See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  23. Check VIAS control solenoid valve circuit (Only M45).

HIGH OR LOW IDLE

Note. Unless otherwise indicated, see SYSTEM & COMPONENT TESTING article for testing procedures.

  1. Check idle speed adjustment. See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  2. Check electric throttle control actuator (QX4 only).
  3. Check TP sensor adjustment (QX4 only). See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  4. Check TP sensor circuit.
  5. Check accelerator pedal position sensor circuit (Except QX4).
  6. Check A/C circuit.
  7. Check engine coolant temperature sensor circuit.
  8. Check for faulty ECM. See appropriate SELF-DIAGNOSTICS article.
  9. Check intake valve timing control solenoid valve circuit (Except I35 & QX4).
  10. Check refrigerant pressure sensor circuit (Except I35 & QX4).
  11. Check fuel pressure regulator. See «BASIC DIAGNOSTIC PROCEDURES»(ref-151802) article.
  12. Check EVAP system.
  13. Check PCV system.
  14. Check Idle Air Control Valve-Auxiliary Air Control (IACV-AAC) valve circuit (QX4 only).

ROUGH IDLE

Note. Unless otherwise indicated, see SYSTEM & COMPONENT TESTING article for testing procedures.

  1. Check ignition timing. See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  2. Check idle speed adjustment. See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  3. Check fuel pump circuit.
  4. Check fuel injector circuits.
  5. Check electric throttle control actuator (Except QX4).
  6. Check ignition circuits.
  7. Check mass airflow sensor circuit.
  8. Check front HO2S circuits.
  9. Check engine coolant temperature sensor circuit.
  10. Check TP sensor circuit.
  11. Check intake valve timing control solenoid valve circuit (Except I35 & QX4).
  12. Check ECM power and ground circuits.
  13. Check A/C circuit.
  14. Check for faulty ECM. See appropriate SELF-DIAGNOSTICS article.
  15. Check park/neutral position switch circuit.
  16. Check power steering pressure sensor/switch circuit.
  17. Check electrical load signal circuit (Except I35 & QX4).
  18. Check fuel pressure regulator. See «BASIC DIAGNOSTIC PROCEDURES»(ref-151802) article.
  19. Check EVAP system.
  20. Check PCV system.
  21. Check Idle Air Control Valve-Auxiliary Air Control (IACV-AAC) valve circuit (QX4 only).
  22. Check TP sensor adjustment (QX4 only). See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.

SLOW RETURN TO IDLE OR NO RETURN TO IDLE

Note. Unless otherwise indicated, see SYSTEM & COMPONENT TESTING article for testing procedures.

  1. Check idle speed adjustment. See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  2. Check electric throttle control actuator (Except QX4).
  3. Check TP sensor adjustment (QX4 only). See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  4. Check TP sensor circuit.
  5. Check accelerator pedal position sensor circuit (I35 only).
  6. Check Idle Air Control Valve-Auxiliary Air Control (IACV-AAC) valve circuit (QX4 only).
  7. Check A/C circuit.
  8. Check engine coolant temperature sensor circuit.
  9. Check for faulty ECM. See appropriate SELF-DIAGNOSTICS article.
  10. Check intake valve timing control solenoid valve circuit (Except I35 & QX4).
  11. Check refrigerant pressure sensor circuit (Except I35 & QX4).
  12. Check fuel pressure regulator. See «BASIC DIAGNOSTIC PROCEDURES»(ref-151802) article.
  13. Check EVAP system.
  14. Check PCV system.

OVERHEATS OR HIGH COOLANT TEMPERATURE

  1. Check ECM power and ground circuits.
  2. Check for faulty ECM. See appropriate SELF-DIAGNOSTICS article.

EXCESSIVE FUEL CONSUMPTION

Note. Unless otherwise indicated, see SYSTEM & COMPONENT TESTING article for testing procedures.

  1. Check ignition timing and idle speed adjustment. See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  2. Check TP sensor adjustment (QX4 only). See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  3. Check fuel injector circuits.
  4. Check Idle Air Control Valve-Auxiliary Air Control (IACV-AAC) valve circuit (QX4 only).
  5. Check electric throttle control actuator (Except QX4).
  6. Check ignition circuits.
  7. Check ignition timing. See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article.
  8. Check mass airflow sensor circuit.
  9. Check front HO2S circuits.
  10. Check engine coolant temperature sensor circuit.
  11. Check TP sensor circuit.
  12. Check fuel pump circuit.
  13. Check ECM power and ground circuits.
  14. Check A/C circuit.
  15. Check vehicle speed sensor circuit.
  16. Check knock sensor circuits.
  17. Check for faulty ECM. See appropriate SELF-DIAGNOSTICS article.
  18. Check park/neutral position switch circuit.
  19. Check intake valve timing control solenoid valve circuit (Except I35 & QX4).
  20. Check fuel pressure regulator. See «BASIC DIAGNOSTIC PROCEDURES»(ref-151802) article.
  21. Check EVAP system.
  22. Check PCV system.
  23. Check refrigerant pressure sensor circuit (Except I35 & QX4).

EXCESSIVE OIL CONSUMPTION

Note. Unless otherwise indicated, see SYSTEM & COMPONENT TESTING article for testing procedures.

  1. Check PCV system.

BATTERY DEAD (UNDER CHARGE)

  1. Check fuel pump circuit.
  2. Check electric throttle control actuator (Except QX4).
  3. Check Idle Air Control Valve-Auxiliary Air Control (IACV-AAC) valve circuit (QX4 only).
  4. Check A/C circuit.

Intermittent Simulation

To reproduce conditions creating an intermittent fault, use following methods

  1. Gently vibrate component.
  2. Heat component.
  3. Freeze component.
  4. Wiggle or bend wiring harness.
  5. Spray component with water.
  6. Turn on all electrical accessories.

Monitor circuit/component voltage or resistance while simulating intermittent. If engine is running, monitor for Diagnostic Trouble Codes (DTCs.) Use test results to identify a faulty component or circuit.

More articles — Engine Controls - Trouble Shooting - No Codes