The Office of Defects Investigations (ODI) is an office within the NHTSA which investigates serious safety problems in the design, construction or performance of vehicles. The NHTSA is authorized to order manufacturers to recall and repair vehicles, if the ODI finds a safety issue. NHTSA investigations for the 2010 Toyota Prius, both ongoing and closed, are listed below:

  1. INVESTIGATION: Braking Performance, Hybrid Vehicle

    NHTSA Preliminary Evaluation #PE10006

    • Status:
    • Date Opened: February 03, 2010
    • Date Closed: July 12, 2010
    • Recall: No recall issued

    Component(s): Service Brakes, Hydraulic
    Service Brakes, Hydraulic:Antilock
    Service Brakes, Hydraulic:Antilock:Control Unit/Module
    Service Brakes, Hydraulic:Foundation Components
    Service Brakes, Hydraulic:Foundation Components:Disc
    Service Brakes, Hydraulic:Power Assist
    Service Brakes, Hydraulic:Power Assist:Hydraulic

    Summary: The subject vehicles are the first model year of a new design generation of the Prius model line.The vehicles are powered by a hybrid drive system that uses both a regenerative braking system, which converts vehicle momentum into electrical energy to be stored in onboard batteries, and a hydraulic brake system more typical of the brake system used on non-hybrid vehicles.As is the case for other similarly designed hybrid vehicles the interaction and management of the two braking systems during ABS braking is complex and requires a sophisticated control system.In a February 9, 2010 Defect Information Report, Toyota advised the agency of its plans to conduct a safety recall to address inconsistent brake feel and increased stopping distances that may occur during braking events requiring ABS operation, such as would occur when braking on rough or low friction road surfaces.Toyota will reprogram the ABS control unit with improved software that addresses this condition.Based on Toyota's action the investigation is closed. ODI will continue to monitor the subject vehicles' performance and will take further action as future circumstances dictate.