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.
1994 Lexus ES 300FACTORY OEM SERVICE PROCEDURE
IAC System Operation
- Ensure engine is at normal operating temperature. Ensure idle speed is 650-750 RPM. See CONNECTING TACHOMETER under INTRODUCTION . Shift transmission into Neutral. Turn A/C off. Connect Jumper Wire (09843-18020) between terminals TE1 and E1 of DLC No. 1. See Figure.
- If engine speed increases to about 1000 RPM for about 5 seconds, then decreases to idle speed of 650-750 RPM, IAC system is okay. If engine speed is not as specified, disconnect jumper wire from DLC No. 1, then go to next procedure.
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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