DTC Test 41: Cruise Control Ecu
WARNING: This page is about a different car, the 1997 Lexus SC 400. However, it is still accessible from the selected car via links, so may be relevant.
Check resistance between ECU terminal No. 13 and ground. If resistance is less than one ohm, check connector. If connector is okay, replace ECU with known good ECU and retest. If resistance is one ohm or more, repair ground circuit and retest.