Shift Solenoids SR & S4
WARNING: This page is about a different car, the 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
Raise and support vehicle. Remove transaxle oil pan. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Remove shift solenoid(s). See Figure. Measure resistance terminal of each solenoid. See Figure. Resistance should be 11-15 ohms at 68°F (20°C). If resistance is not as specified, replace faulty solenoid.
To check shift solenoid S4 operation, connect solenoid terminal to battery positive using a test lead with an in-line 23-watt bulb. Connect solenoid body to ground. See Figure. With power supplied to solenoid, ensure solenoid valve moves outward. With power disconnected, ensure solenoid valve moves inward. If solenoid does not operate as described, replace solenoid. If solenoid operates, diagnose valve body malfunction.