GMC Terrain 2025 - Page 222

GMC Terrain/Terrain Denali Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-18552429) - 2025
Driving and Operating 221
Trailer Tires
S
p
ecial Trailer (ST) tires differ from vehicle tires.
Trailer tires are designed with stiff sidewalls
to help prevent sway and to support heavy
loads. These features can make it difficult to
determine if the trailer tire pressures are low
only based on avisual inspection.
Always check all trailer tire pressures before
each trip when the tires are cool. Low trailer tire
pressure is aleading cause of trailer tire blow-
outs.
Trailer tires deteriorate over time. The trailer
tire sidewall will show the week and year
the tire was manufactured. Many trailer
tire manufacturers recommend replacing tires
more than six years old.
Overloading is another leading cause of trailer
tire blow-outs. Never load your trailer with
more weight than the tires are designed to
support. The load rating is located on the trailer
tire sidewall.
Always know the maximum speed rating for
the trailer tires before driving. This may be
significantly lower than the vehicle tire speed
rating. The speed rating may be on the trailer
tire sidewall. If the speed rating is not shown,
th
e default trailer tire speed rating is 105 km/h
(65 mph).
Conversions and Add-Ons
Add-On Electrical Equipment
{ Warning
T
he Data Link Connector (DLC) is used for
ve
hicle service and Emission Inspection/
Maintenance testing. See Malfunction
Indicator Lamp (Check Engine Light) 393.
Adevice connected to the DLC — such
as an aftermarket fleet or driver-behavior
tracking device — may interfere with
vehicle systems. This could affect vehicle
operation and cause acrash. Such devices
may also access information stored in the
vehicle’s systems.
Caution
Some electrical equipment can damage the
vehicle or cause components to not work
and would not be covered by the vehicle
warranty. Always check with your dealer
before adding electrical equipment.
Add-on equipment can drain the vehicle's 12-
vo
lt battery, even if the vehicle is not operating.
The vehicle has an airbag system. Before
attempting to add anything electrical to the
vehicle, see Servicing the Airbag-Equipped
Vehicle 355 and Adding Equipment to the
Airbag-Equipped Vehicle 355.