Plano, TX – Nov. 30, 2017 – Toyota Motor Engineering and Manufacturing has recalled more than 39,000 vehicles potentially equipped with defective fuses, according to documentation submitted to the National Highway Transportation Safety Administration. The campaign affects 2012-2015 Toyota Prius PHV plug-in hybrid sedans manufactured between July 20, 2011 and Jan. 8, 2015. Toyota is unsure what percentage of the vehicles referenced in the recall actually contain the defective components.
The affected sedans may contain electric vehicle fuses prone to fracture following excessive thermal stress. Normally, this condition develops during high-load driving maneuvers such as prolonged ascents. In instances in which the fuse fractures and subsequently opens while in operation, the vehicle may lose power or continue to function but with reduced capacity. This defect poses a serious risk to owners, as the sudden loss of motive power could increase the likelihood of an accident. However, Toyota has yet to receive reports linking the damage-prone fuse to any accidents or injuries.
Timeline of Events
Toyota received a field report from the European market in August 2014 detailing an instance in which a Prius PHV sedan lost motive power, triggering interior warning lights, according to a chronology document submitted to the NHTSA. A dealer determined that the hybrid battery was the root cause of the event and installed a replacement, eventually sending the damaged original to the Toyota home office for further evaluation. Here, engineers found that the EV fuse was fractured and ultimately attributed the problem to an installation error. Toyota reviewed its production processes and eventually determined the fuse was bent during manufacturing, inhibiting its durability. The automaker updated its processes to prevent similar problems in February 2015.
In March 2015, Toyota received additional reports from the U.S. market. Engineers for the company inspected fuses from six vehicles, four of which showed signs of fracturing. Toyota began to consider that these defective parts were not the result of flawed manufacturing workflows, but the product of deeper mechanical issues, specifically excessive current generated during high-load driving. However, the car company could not replicate the issue in-house and put a hold on ongoing investigations related to the defective fuses in June 2017.
Then, one month later, another report came in outlining a situation in which an owner in Japan lost motive power in the middle of an intersection. The EV fuse installed in the vehicle was fractured. The driver told Toyota officials that he frequently drove up inclines under electric power only. Engineers attempted to replicate the problem by driving the exact same route the owner had driven but were once again unable to do so. However, they did record data that indicated prolonged large current flow. This information led them to perform additional tests during which vehicles were subjected to multiple slow-speed ascents. During these trials, the engineers were able to replicate the fuse fracture.
On Nov. 9, 2017, Toyota launched a voluntary safety recall to address the issue. The automaker notified dealers Nov. 14.
Toyota has directed dealers to replace the EV fuses in affected vehicles free of charge, according to an NHTSA recall acknowledgement document. The car manufacturing company intends to notify owners via first-class mail Jan. 8, 2018. Those in need of more immediate assistance can contact Toyota customer service personnel at (800) 331-4331. Callers should use the internal recall identification code H0R. Owners can also contact the NHTSA directly using the toll-free Vehicle Safety Hotline at (888) 327-4236.