1995 Lexus ES 300FACTORY OEM SERVICE PROCEDURE

Air Assist System

  1. 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. See COMPONENT LOCATIONS  under INTRODUCTION.
  2. Engine speed should increase to about 900-1300 RPM for about 10 seconds, then decrease to idle speed of 650-750 RPM. Stop engine. Disconnect air hose from air assist hose block. See Figure. Plug hose end, and cap off the hose fitting on the air assist hose block.
  3. Start engine. If engine idles at about 500 RPM or less (or if engine stalls), air assist system is okay. If engine does not operate as specified, check for vacuum leak, then go to next procedure.
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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