Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2001 Infiniti Q45 BaseFACTORY OEM SERVICE PROCEDURE
Engine Controls - Self-Diagnostics
- Introduction
- Self-Diagnostic System
- Programming
- Summary
- Diagnostic Trouble Code Definitions
- Diagnostic Tests
- Mil 0208: Cooling Fan Circuit
- DTC P0100: Mass Airflow (MAF) Sensor
- DTC P0105: Absolute Pressure (AP) Sensor
- DTC P0110: Intake Air Temperature (IAT) Sensor
- DTC P0115 Or P0125: Engine Coolant Temperature (ECT) Sensor
- DTC P0120: Throttle Position (TP) Sensor
- DTC P0130 Or P0150: Left Side Or Right Side Front Heated Oxygen Sensor (Ho2S)
- DTC P0131 Or P0132: Left Side Front Heated Oxygen Sensor (Ho2S), Or DTC P0151 Or P0152: Right Side Front Heated Oxygen Sensor (Ho2S)
- DTC P0133: Left Side Front Heated Oxygen Sensor (Ho2S), Or DTC P0153: Right Side Front Heated Oxygen Sensor (Ho2S)
- DTC P0134 Or P0154: Front (Right & Left) Ho2S Sensor
- DTC P0135 Or P0155: Front (Right & Left) Ho2S Heater
- DTC P0137, P0138, P0139, P0140, P0157, P0158, P0159 Or P0160: Rear Ho2S
- DTC P0141 Or P0161: Rear Ho2S Heater
- DTC P0171, P0172, P0174 Or P0175: Fuel Injection System Function (Right & Left Bank)
- DTC P0180: Fuel Tank Temperature (FTT) Sensor
- DTC P0300-P0308: Cylinder Or Multiple Cylinder Misfire
- DTC P0325 Or P0330: Left Or Right Side Knock Sensor
- DTC P0335 Or P1336: Crankshaft Position (CKP) Sensor
- DTC P0340: Camshaft Position (CMP) Sensor
- DTC P0400: EGR Function
- DTC P0402: EGR Control BACKPRESSURE Transducer (EGRC-BPT)
- DTC P0420 Or P0430: Three-Way Catalyst Function
- DTC P0440, P0455 Or P1440: EVAP Control System
- DTC P0443: EVAP Canister Purge Volume Control Valve (EVAP-CPVCV)
- DTC P0446: EVAP Canister Vent Control Valve (EVAP-CVCV)
- DTC P0450: EVAP Control System Pressure Sensor (EVAP-CSPS)
- DTC P0500: Vehicle Speed Sensor (VSS)
- DTC P0505: Idle Air Control Valve-Auxiliary Air Control (IACV-AAC) Valve
- DTC P0510: Closed Throttle Position (TP) Switch
- DTC P0600: A/T Communication Line, Or P1605: A/T Diagnostic Communication Line
- DTC P0605: ECM
- DTC P1105: Manifold Absolute Pressure (Map)/Barometric Pressure (BARO) Solenoid
- DTC P1110: Left Side, Or DTC P1135: Right Side Intake Valve Timing Control (IVTC)
- DTC P1120: Secondary Throttle Position Sensor (STPS)
- DTC P1125: Tandem Throttle Position (TP) Sensor
- DTC P1140: Left Side, Or DTC P1145: Right Side Intake Valve Timing Control (IVTC) Position Sensor
- DTC P1148 Or P1168: Closed Loop Control
- DTC P1210: Traction Control System (TCS) Signal Circuit
- DTC P1220: Fuel Pump Control Module (FPCM)
- DTC P1320: Ignition Signal
- DTC P1336: Crankshaft Position (CKP) Sensor (Pos)
- DTC P1400: EGRC Solenoid
- DTC P1401: EGR Temperature Sensor
- DTC P1402: EGR Function
- DTC P1440: EVAP Control System
- DTC P1444: EVAP Canister Purge Volume Control Valve (EVAP-CPVCV)
- DTC P1446: EVAP Canister Vent Control Valve (EVAP-CVCV)
- DTC P1447: EVAP Control System Purge Flow Monitoring
- DTC P1448: EVAP Canister Vent Control Valve (EVAP-CVCV)
- DTC P1490: Vacuum Cut Valve By-Pass Valve
- DTC P1491: Vacuum Cut Valve By-Pass Valve
- DTC P1492: EVAP Canister Purge Control Solenoid (EVAP-CPCS)
- DTC P1493: EVAP Canister Purge Control Valve (EVAP-CPCV)
- DTC P1605: Automatic Transmission (A/T) Control
- DTC P1706: Park/Neutral Position (PNP) Switch
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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