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.
1992 Lexus ES 300 AutomaticFACTORY OEM SERVICE PROCEDURE
Engine Main Relay
- Disconnect engine main relay. See Fig 1. Use an ohmmeter to check for continuity between relay terminals No. 1 and 3. See Fig 1. Check for continuity between relay terminals No. 2 and 4. Ensure continuity is not present between relay terminals No. 4 and 5. If continuity is not as specified, replace relay.
- Apply battery voltage between relay terminals No. 1 and 3. Using an ohmmeter, check for continuity between relay terminals No. 4 and 5. Ensure continuity is not present between relay terminals No. 2 and 4. If continuity readings are not as specified, replace relay.
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.