Transponder Key Coil
WARNING: This page is about a different car, the 2002 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.
Check that continuity exists between terminals No. 1 and 2. See CONNECTOR IDENTIFICATION . If continuity is not as specified, replace the coil. See TRANSPONDER KEY COIL & AMPLIFIER under REMOVAL & INSTALLATION.