This bulletin applies to 2016-2020 Toyota Mirai vehicles equipped with hydrogen engines. During vehicle inspections, when the under covers are removed, debris may be found on the under cover near the end of the hydrogen tank. Upon closer inspection, the debris is found to be coming from the end protector of the tank.
During vehicle use, heat and ultraviolet light can cause degradation of the tank protector causing the foam to come off.
This protector is added to shield the tank during the production process and does not negatively affect the tank and is only an appearance concern. It is recommended to clean the under covers before reinstalling.