Toyota 2014 Sienna Manual page 382

2-5. Driving information
Positions for towing hitch receiver
Connecting trailer lights
Please consult your dealer when installing trailer lights, as incorrect
installation may cause damage to the vehicle's lights. Please take
care to comply with your state's laws when installing trailer lights.
382
SIENNA_OM_OM45483U_(U)
Hitch receiver pin hole posi-
tion: 37.3 in. (949.8 mm)