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 Lexus GS 300FACTORY OEM SERVICE PROCEDURE
Control Units
CONTROL UNITS LOCATION
| Component | Location |
|---|---|
| ABS & TRAC & VSC ECU | Behind left side of dash. See Figure. |
| A/C Control Assembly | Behind center of dash. See Figure. |
| Blower Motor Controller | Behind right side of dash. See Figure. |
| Body ECU No. 1 | In passenger side J/B. See Figure. |
| Body ECU No. 2 | In driver side J/B. See Figure. |
| Center Air Bag Sensor Assembly | Behind center of dash, forward of center console. See Figure. |
| Driver Door ECU | In driver's door. See Figure. |
| Engine Control Module | At left side of engine compartment, in ECU box. See Figure. |
| Front Passenger Door ECU | In right front door. See Figure. |
| Fuel Pump Control ECU | At left side of luggage compartment. See Figure. |
| Gateway ECU | Behind left side of dash. See Figure. |
| Headlight Beam Level Control ECU | At left front corner of engine compartment. See Figure. |
| Headlight Control ECU (Left) | Behind left headlight. See Figure. |
| Headlight Control ECU (Right) | Behind right headlight. See Figure. |
| Moon Roof Control ECU | In front of moon roof opening. See Figure. |
| Navigation ECU | At right rear corner of luggage compartment. See Figure. |
| Power Seat ECU | Under driver's seat. See Figure. |
| PPS ECU | Behind left side of dash. See Figure. |
| Rear Door ECU (Left) | In left rear door. See Figure. |
| Rear Door ECU (Right) | In right rear door. See Figure. |
| Shift Lock ECU | Under center console, near selector lever. See Figure. |
| Tilt & Telescopic ECU | Behind left side of dash. See Figure. |
| Wireless Door Lock Control ECU | At right side of luggage compartment. See Figure. |
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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