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 ES 300FACTORY OEM SERVICE PROCEDURE
Resistance Check
- Remove engine cover. Disconnect connector from Oil Control Valve (OCV) to be tested. Oil control valves are located at front top of each cylinder head. On ES300, left OCV has a 2-pin connector with Green/Yellow and Green/Red wires. Right OCV has a 2-pin connector with Green/White and Green wires. On RX300, left OCV has a 2-pin connector with Green/Yellow and Green/Red wires. Right OCV has a 2-pin connector with Green/White and Yellow/Black wires.
- On all models, measure resistance between OCV terminals. Resistance should be 6.9-7.9 ohms at 68°F (20°C). If resistance is not 6.9-7.9 ohms, replace OCV.
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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