NHTSA Complaint #11702258 — 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.