Toyota Says Tundra May Have Trailering Issue
2018-2019 Toyota Tundra trucks equipped with a 5.7L engine and integrated trailer brake controllers may exhibit an intermittent “Trailer Disconnected” message in the combination meter while towing a trailer. The brake control relay with bracket should not be replaced as part of this bulletin. It will be necessary to reprogram the PCM with software version 14.00.019 or later using Techstream 2.0 or Techstream LITE.
The previous calibration ID is either 8954F0C050 or 8954F0C040. The NEW calibration ID is 8954F0C060.
According to Toyota, the GR8 battery diagnostic station must be used in power supply mode to maintain voltage above 11.4V while flash reprogramming.