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 Lexus GS 430FACTORY OEM SERVICE PROCEDURE
Body Control Systems
- Description & Operation
- Component Locations
- Trouble Shooting
- Self-Diagnostic System
- Connector Identification
- Circuit Tests
- Anti-Theft Horn Circuit
- Anti-Theft Indicator Circuit
- Brake Fluid Level Warning Switch Circuit
- Clock Circuit
- Driver Buckle Switch Circuit
- Generator "L" Terminal Circuit (W/ Daytime Running Lights Only)
- Hazard Switch Circuit
- Headlight Relay Circuit
- Heater Main Relay Circuit
- Hood Courtesy Switch Circuit
- Horn Circuit
- Illumination Circuit
- Key Unlock Warning Switch Circuit
- Lamp Failure Sensor Circuit
- Light Control Switch Circuit
- Luggage Compartment Door Lock & Unlock Switch Circuit
- Luggage Compartment Courtesy Switch Circuit
- Luggage Compartment Door Opener Motor Circuit
- Luggage Compartment Door Opener Switch Circuit
- Mirror Switch Circuit
- Parking Brake Switch Circuit
- Pattern Select Switch Circuit
- Power Source Circuit (Body Ecu No. 1)
- Power Source Circuit (Body Ecu No. 2)
- PWS Circuit
- Rear Defogger Relay Circuit
- Stop Light Switch Circuit
- Taillight Relay Circuit
- Wireless Door Lock Buzzer Circuit
- Wireless Door Lock Tuner Circuit
- Component Tests
- Pin Voltage Tests
- Removal & Installation
- Wiring Diagrams
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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