On June 14, 2016, the Office of Defects Investigation (ODI) opened Preliminary Evaluation PE16-006 to investigate 135 complaints alleging incidents of yaw rate sensor malfunctions resulting in unexpected Vehicle Stability Control (VSC) activations and steering pull while driving in model year (MY) 2001-2002 Toyota Sequoia vehicles.ODI identified a total of 958 incidents in complaints provided by Toyota or submitted to ODI by consumers.ODI conducted the following work to assess the alleged defect in the subject vehicles: 1) evaluated the design of the subject yaw rate sensor; 2) initiated vehicle testing and instrumentation; 3) performed failure analysis on subject components collected from the field; 4) analyzed field data for evidence of system faults; and 5) reviewed the performance of the subject system in fault simulations testing conducted by Toyota.ODI review indicated that an overwhelming majority of incidents are related to flashing VSC slip indicators on the instrument panel accompanied by warning buzzers and grinding noise or vibration caused by pulsed brake application to one of the front wheels.Yaw rate sensor malfunctions resulting in VSC brake applications is accompanied by a brief duration of longitudinal deceleration with minimal changes in vehicle speed and will not result in abrupt lane change or loss of vehicle control due to steering controllability.This preliminary evaluation is closed.The closing of this investigation does not constitute a finding that a safety related defect does not exist.For additional information, see the closing resume appendix and the investigation file for PE16-006.
