GMC Yukon 2025 - Trailer Towing

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-17942154) - 2025
286 Driving and Operating
Warning (Continued)
•
Do
not move the vehicle if someone is
in the path of the trailer. Some parts of
the trailer might be underwater and not
visible to people who are assisting in
launching the boat.
Disconnect the wiring to the trailer before
ba
cking the trailer into the water to prevent
damage to the electrical circuits on the
trailer. Reconnect the wiring to the trailer
after removing the trailer from the water.
If the trailer has electric brakes that can
function when the trailer is submerged, leave
the electrical trailer connector attached to
maintain trailer brake functionality while on
the boat ramp.
To back the trailer into the water:
1. If equipped, place the vehicle in Four-Wheel
Drive High or Automatic Four-Wheel Drive.
2. Slowly back down the boat ramp only
until the boat is floating, but no further
than necessary.
3. Press and hold the brake pedal, but do not
shift into P (Park).
4. Have someone place chocks under the front
w
heels of the vehicle.
5. Gradually release the brake pedal to allow
the chocks to support the load of the trailer.
6. Reapply the brake pedal. Then apply the
parking brake and shift into P (Park).
7. Release the brake pedal.
Pulling the Trailer from the Water
To pull the trailer from the water:
1. Press and hold the brake pedal.
2. Start the vehicle and shift into (D) Drive.
3. Release the parking brake.
4. Let up on the brake pedal.
5. Drive slowly until the tires are clear of
the chocks.
6. Stop and have someone pick up and store
the chocks.
7. Slowly pull the trailer from the water.
8. Once the vehicle and trailer have been
driven from the sloped part of the boat
ramp, the vehicle can be shifted from four-
wheel-drive high. Shift into the drive mode
that is appropriate for the road conditions.
Caution
If the vehicle tires begin to spin and the
vehicle begins to slide toward the water,
remove your foot from the accelerator
pedal and apply the brake pedal. Seek help
to have the vehicle towed up the ramp.
Maintenance when Trailer Towing
A
vehicle used to tow trailers requires service
more often. See Maintenance Schedule 3 398. It
is especially important to check the engine oil,
axle lubricant, belts, cooling system, and brake
system before and during each trip.
Check periodically that all nuts and bolts on the
trailer hitch are tight.
Engine Cooling when Trailer Towing
The cooling system may temporarily overheat
during severe operating conditions. See Engine
Overheating 3328.
Trailer Towing
If equipped with adiesel engine, see the
Duramax diesel supplement.