IAC Valve Resistance
WARNING: This page is about a different car, the 1995 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect IAC valve connector. See COMPONENT LOCATIONS under INTRODUCTION. At IAC valve connector, measure resistance between terminals +B and USC, and between terminals +B and RSO. See Figure. If resistance is not 19.3-22.3 ohms at 68°F (20°C), replace IAC valve. If resistance is as specified, reconnect IAC valve connector. Go to next procedure.