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.
2003 Infiniti Q45FACTORY OEM SERVICE PROCEDURE
Automatic Transaxle
- Index For DTC
- Precautions
- Preparation
- A/T Fluid
- A/T Control System
- On Board Diagnostic (OBD) System
- Trouble Diagnosis
- DTC Inspection Priority Chart
- Fail-Safe
- How To Perform Trouble Diagnosis For Quick and Accurate Repair
- A/T Electrical Parts Location
- Circuit Diagram
- Inspections Before Trouble Diagnosis
- Check Before Engine is Started
- Check at Idle
- Cruise Test - Part 1
- Cruise Test - Part 2
- Cruise Test - Part 3
- Vehicle Speed When Shifting Gears
- Vehicle Speed When Performing and Releasing Complete Lock-up
- Vehicle Speed When Performing and Releasing Slip Lock-up
- Symptom Chart
- TCM Input/Output Signal Reference Values
- Consult-II
- Diagnostic Procedure Without CONSULT-II
- DTC U1000: Can Communication Line
- DTC P0615: Start Signal Circuit
- DTC P0705: Park/Neutral Position Switch
- DTC P0720: Vehicle Speed Sensor A/T (Revolution Sensor)
- DTC P0725: Engine Speed Signal
- DTC P0740: Torque Converter Clutch Solenoid Valve
- DTC P0744: A/T TCC S/V Function (Lock-Up)
- DTC P0745: Line Pressure Solenoid Valve
- DTC P1701: Transmission Control Module (Power Supply)
- DTC P1702: Transmission Control Module (Ram)
- DTC P1703: Transmission Control Module (ROM)
- DTC P1704: Transmission Control Module (EEPROM)
- DTC P1705: Throttle Position Sensor
- DTC P1710: A/T Fluid Temperature Sensor Circuit
- DTC P1716: Turbine Revolution Sensor
- DTC P1721: Vehicle Speed Sensor MTR
- DTC P1730: A/T Interlock
- DTC P1731: A/T 1ST Engine Braking
- DTC P1752: Input Clutch Solenoid Valve
- DTC P1754: Input Clutch Solenoid Valve Function
- DTC P1757: Front Brake Solenoid Valve
- DTC P1759: Front Brake Solenoid Valve Function
- DTC P1762: Direct Clutch Solenoid Valve
- DTC P1764: Direct Clutch Solenoid Valve Function
- DTC P1767: High And Low Reverse Clutch Solenoid Valve
- DTC P1769: High And Low Reverse Clutch Solenoid Valve Function
- DTC P1772: Low Coast Brake Solenoid Valve
- DTC P1774: Low Coast Brake Solenoid Valve Function
- DTC P1815: Manual Mode Switch
- DTC P1841: ATF Pressure Switch 1
- DTC P1843: ATF Pressure Switch 3
- DTC P1845: ATF Pressure Switch 5
- DTC P1846: ATF Pressure Switch 6
- Park/Neutral Position, Manual Mode, Brake And Throttle Position Switch Circuit
- Trouble Diagnosis For Symptoms
- Wiring Diagram - AT - NONDTC
- A/T CHECK Indicator Lamp Does Not Come On SYMPTOM:
- Diagnostic Procedure
- Engine Cannot Be Started In "P" or "N" Position
- In "P" Position, Vehicle Moves When Pushed
- In "N" Position, Vehicle Moves
- Large Shock ( "N" to "D" Position)
- Vehicle Does Not Creep Backward In "R" Position
- Vehicle Does Not Creep Forward In "D" position
- Vehicle Cannot Be Started From D1
- A/T Does Not Shift: D1 --> D2
- A/T Does Not Shift: D2 --> D3
- A/T Does Not Shift: D3 --> D4
- A/T Does Not Shift: D4 --> D5
- A/T Does Not Perform Lock-up
- A/T Does Not Hold Lock-up Condition
- Lock-up Is Not Released
- Engine Speed Does Not Return To Idle
- Cannot Be Changed to Manual Mode
- A/T Does Not Shift: 5th gear --> 4th gear
- A/T Does Not Shift: 4th gear --> 3rd gear
- A/T Does Not Shift: 3rd gear --> 2nd gear
- A/T Does Not Shift: 2nd gear --> 1st gear
- Vehicle Does Not Decelerate By Engine Brake
- Shift Control System
- A/T Shift Lock System
- On-Vehicle Service
- Transmission Assembly
- Overhaul
- Disassembly
- Repair For Component Parts
- Assembly
- Service Data And Specifications (SDS)
- General Specifications
- Vehicle Speed When Shifting Gears
- Vehicle Speed When Performing and Releasing Complete Lock-up
- Vehicle Speed When Performing and Releasing Slip Lock-up
- Stall Speed
- Line Pressure
- Solenoid Valves
- A/T Fluid Temperature Sensor
- Turbine Revolution Sensor
- Revolution Sensor
- Reverse Brake
- Total End Play
- Bearing Race For Adjusting Total End Play
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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