2013 Toyota Tundra Regular Cab Owners Manual - Page 255

2-5. Driving information ● The trailer is level when it is hitched. Do not drive if the trailer is not level, and check for improper tongue weight, overloading, worn suspension, or other possible causes. ● The trailer cargo is securely loaded. ● The rear view mirrors conform to all applicable federal, state/provincial or local regulations. If they do not, install rear view mirrors appropriate for towing purposes. ● Depress TOW/HAUL button (if equipped)