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.
2004 Infiniti Q45FACTORY OEM SERVICE PROCEDURE
Brake Control System
- Precautions
- Preparation
- On-Vehicle Service
- System Description
- Can Communication
- Trouble Diagnosis
- How To Proceed With Diagnosis
- Component Installation Location
- Schematic
- Wiring Diagram
- Control Unit Input/Output Signal Standard
- Consult-II Functions
- For Fast And Accurate Diagnosis
- Basic Inspection
- Inspection: 1 Wheel Sensor System
- Inspection: 2 Engine System
- Inspection: 3 VDC/TCS/Abs Control Unit System
- Inspection 4: Pressure Sensor And Circuit Between Pressure Sensor And VDC/TCS/Abs Control Unit
- Inspection 5: Steering Angle Sensor And Circuit Between Steering Angle Sensor And VDC/TCS/Abs Control Unit
- Inspection 6: Yaw Rate/Side G-Sensor And Circuit Between Yaw Rate/Side G-Sensor And VDC/TCS/Abs Control Unit
- Inspection 7: Solenoid, VDC Switching Valve, And Circuits
- Inspection 8: Actuator Motor, Motor Relay, And Circuit
- Inspection 9: Actuator Relay And Circuit
- Inspection 10: Stop Lamp Switch And Circuit
- Inspection 11: VDC/TCS/Abs Control Unit Power Circuit
- Inspection 12: When "Shift Position Error" Appears In Self-Diagnosis Results Display
- Inspection 13: When "Emergency Brake" Appears On Self-Diagnosis Results Display
- Inspection 14: When "Steering Angle Sensor Has Not Been Corrected" Appears On Self-Diagnosis Results Display
- Inspection 15: Brake Fluid Level In Reservoir Tank, Communication Circuit Between VDC/TCS/Abs Control Unit And Brake Fluid Level Sensor
- Inspection 16: Can Communications Lines, VDC/TCS/Abs Control Unit And Steering Angle Sensor System
- Inspecting Components
- Symptom 1: Abs Works Frequently.
- Symptom 2: Unexpected Pedal Reaction
- Symptom 3: Long Stopping Distance
- Symptom 4: Abs Does Not Work.
- Symptom 5: Pedal Vibration And Noise
- Symptom 6: VDC Off Indicator Lamp Does Not Illuminate.
- Symptom 7: Slip Indicator Lamp Does Not Illuminate.
- Symptom 8: Vehicle Behaves Jerkily During VDC/TCS/Abs Operation.
- Wheel Sensors
- VDC/TCS/Abs Control Unit
- Sensor Rotor
- VDC/TCS/Abs Actuator
- G Sensor
- Steering Angle Sensor
Factory Service Tools
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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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