One problem related to brake light on has been reported for the 2018 Toyota Highlander. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2018 Toyota Highlander based on all problems reported for the 2018 Highlander.
While driving the brake assist vacuum pump fails to provide adequate vacuum for the power brake vacuum assist. Resulting is a loss of braking power. A brake light illuminates intermitantly on the dash panel and possibly an audio warning and error message. Plus no error codes are stored in memory for future diagnosis. This happens whether on a rural road, city street or highway. A previous recall was issued for the 2018 Toyota Highlander for this same issue but not for this specific Highlander.