Adaptive Cruise Control problems of the 2017 Toyota RAV4

While driving the vehicle on an uphill stretch of highway with cruise control set at approximately 65 mph, the vehicle suddenly slowed down without warning. A distinct clunk was heard at the same moment. The cruise control system attempted to restore speed, and the engine became noticeably louder, but the vehicle struggled to return to the set speed. The driver tapped the brake to disengage cruise control and manually pressed the accelerator to resume normal speed. The trip was completed without additional events. After parking, the check engine light illuminated and the cruise control system became disabled on all subsequent drives. No warning indicators were present at the time of the initial failure, and there were no vehicles ahead that would have triggered the collision-avoidance system. Two days later, the vehicle became an intermittent no-start and eventually failed to start entirely. The vehicle was towed to a dealership for inspection. Technicians confirmed an electrical malfunction and reported that the multiplex ecu was likely experiencing an internal short. A parasitic draw test showed an abnormally high current draw of approximately 113 MA, which disappeared when the dome-light fuse and later the multiplex ecu were disconnected. The failure is intermittent and appears to involve an internal electrical short within the multiplex ecu. The sudden loss of cruise control function, abrupt deceleration, and subsequent intermittent electrical behavior created a safety risk, as the electrical malfunction occurred without warning while the vehicle was in motion. The issue was confirmed by a dealership service department.

My 2017 Toyota Rav4 xle is experiencing unsafe behavior with the adaptive cruise control (acc). When driving around modest or slight turns, the acc frequently loses tracking of the vehicle ahead and suddenly accelerates, then harshly brakes once it reacquires the vehicle. This creates a jerking motion and significantly reduces my confidence in the system. On one occasion while traveling approximately 45 miles per hour on a slight curve, the acc began rapidly accelerating toward the vehicle in front of me as if no vehicle was there, forcing me to perform an emergency manual takeover and disengage the acc to avoid a potential rear end collision. This issue is repeatable and appears to be related to how the acc detects vehicles ahead while cornering. I am requesting that this behavior be investigated as a potential safety defect.

With rain and snow the sensor start beeping and warning of objects in front of the vehicle when there are nothing. Driving in snow gets the sensors blocked and you cant use the cruise control.