One problem related to rearview system braking has been reported for the 2017 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2017 Toyota Sienna based on all problems reported for the 2017 Sienna.
Wire harness section which controls the parking collision warning and rear cross traffic warning is frayed, causing failure. This failure was determined by the dealer to be caused by mud packing into the rear bumper cavity. Dealer wanted over $1,000 to fix. Denied warranty, due to the cause being "an outside influence". There is no way to effectively wash the inside of the bumper without removing the bumper. If I pay for a new wire harness, the issue will re-occur. This poses an elevated risk to my family and any occupants of the vehicle, as key safety features must be disabled.