1997 Lexus ES 300FACTORY OEM SERVICE PROCEDURE

IAC Valve Resistance

Disconnect IAC valve connector. Measure resistance between terminals +B and RSC, and between terminals +B and RSO at IAC valve. See Fig 2. If resistance is not 17-25 ohms (cold) or 22-29 ohms (hot), replace IAC valve. If resistance is as specified, reconnect IAC valve connector. Go to next procedure.

Fig 1: Identifying Data link Connector (DLC) No. 1 Connector Terminals
G97E06179Courtesy of Β© TOYOTA, LICENSE AGREEMENT TMS1002
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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