2010 GMC YUKON tow

Weight of the Trailer Tongue
The tongue load (A) of any trailer is very important
because it is also part of the vehicle weight. The Gross
Vehicle Weight (GVW) includes the curb weight of the
vehicle, any cargo carried in it, and the people who will
be riding in the vehicle as well as trailer tongue weight.
Vehicle options, equipment, passengers and cargo in
the vehicle reduce the amount of tongue weight the
vehicle can carry, which will also reduce the trailer
weight the vehicle can tow. SeeLoading the Vehicle
on
page 5‑31for more information about the vehicle's
maximum load capacity.
Trailer tongue weight (A) should be 10 percent to
15 percent and fifth wheel or gooseneck kingpin weight
should be 15 to 25 percent of the loaded trailer weight
up to the maximums for vehicle series and hitch type
shown below:
Vehicle Series Hitch Type Maximum
Tongue Weight
1500 Weight Carrying 272 kg (600 lbs)
2500 Weight Carrying 453 kg (1,000 lbs)
1500 Weight Distributing 499 kg (1,100 lbs)
2500 Weight Distributing 680 kg (1,500 lbs)
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Do not exceed the maximum allowable tongue weight
for the vehicle. Choose the shortest hitch extension that
will position the hitch ball closest to the vehicle. This will
help reduce the effect of trailer tongue weight on the
rear axle.
Trailering may be limited by the vehicle's ability to carry
tongue weight. Tongue or kingpin weight cannot cause
the vehicle to exceed the GVWR (Gross Vehicle Weight
Rating) or the RGAWR (Rear Gross Axle Weight
Rating). See“Total Weight on the Vehicle's Tires”
later in this section for more information.
After loading the trailer, weigh the trailer and then the
tongue, separately, to see if the weights are proper.
If they are not, adjustments might be made by moving
some items around in the trailer.
Total Weight on the Vehicle's Tires
Be sure the vehicle's tires are inflated to the inflation
pressures found on the Certification label on the drivers
door or see Loading the Vehicle
on page 5‑31for more
information. Make sure not to exceed the GVWR limit
for the vehicle, or the RGAWR, with the tow vehicle and
trailer fully loaded for the trip including the weight of the
trailer tongue. If using a weight distributing hitch, make
sure not to exceed the RGAWR before applying the
weight distribution spring bars.
Weight of the Trailering Combination
It is important that the combination of the tow
vehicle and trailer does not exceed any of its weight
ratings —GCWR, GVWR, RGAWR, Trailer Weight
Rating or Tongue Weight. The only way to be sure it is
not exceeding any of these ratings is to weigh the tow
vehicle and trailer combination, fully loaded for the trip,
getting individual weights for each of these items.
Hitches
The correct hitch equipment helps maintain combination
control. Most small-to-medium trailers can be towed
with a weight carrying hitch which simply features a
coupler latched to the hitch ball. Larger trailers may
require a weight distributing hitch that uses spring bars
to distribute the trailer tongue weight among the two
vehicle and trailer axles. See “Weight of the Trailer
Tongue” earlier in this section for rating limits with
various hitch types.
If a step-bumper hitch will be used, the bumper could
be damaged in sharp turns. Make sure there is ample
room when turning to avoid contact between the trailer
and the bumper.
Consider using sway controls with any trailer. Ask a
trailering professional about sway controls or refer
to the trailer manufacturer's recommendations and
instructions.
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Weight‐Distributing Hitch Adjustment
A:Body to Ground Distance
B: Front of Vehicle
When using a weight-distributing hitch, the spring bars
should be adjusted so the distance (A) is the same after
coupling the trailer to the tow vehicle and adjusting the
hitch.
Safety Chains
Always attach chains between the vehicle and the
trailer. Cross the safety chains under the tongue of the
trailer to help prevent the tongue from contacting the
road if it becomes separated from the hitch. Instructions
about safety chains may be provided by the hitch
manufacturer or by the trailer manufacturer. If the
trailer being towed weighs up to 5,000 lbs (2 271 kg)
with a factory-installed step bumper, safety chains
may be attached to the attaching points on the bumper,
otherwise, safety chains should be attached to holes
on the trailer hitch platform. Always leave just enough
slack so the combination can turn. Never allow safety
chains to drag on the ground.
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Tow/Haul Mode
Pressing this button
at the end of the shift
lever turns on and off
the tow/haul mode.
This indicator light on
the instrument panel
cluster comes on when
the tow/haul mode is on.
Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. See Tow/Haul Mode
on
page 3‑39for more information. Tow/Haul is designed to be most effective when
the vehicle and trailer combined weight is at least
75 percent of the vehicle's Gross Combined Weight
Rating (GCWR). See
“Weight of the Trailer” earlier in
the section. Tow/Haul is most useful under the following
driving conditions:
.When pulling a heavy trailer or a large or heavy
load through rolling terrain.
.When pulling a heavy trailer or a large or heavy
load in stop and go traffic.
.When pulling a heavy trailer or a large or heavy
load in busy parking lots where improved low
speed control of the vehicle is desired.
Operating the vehicle in Tow/Haul when lightly loaded
or with no trailer at all will not cause damage. However,
there is no benefit to the selection of Tow/Haul when the
vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission
driving characteristics and reduced fuel economy.
Tow/Haul is recommended only when pulling a heavy
trailer or a large or heavy load.
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The ITBC system is powered through the vehicle's
electrical system. Turning the ignition off will also turn
off the ITBC system. The ITBC system is fully functional
only when the ignition is in ON or in RUN.
The ITBC system can only be used with trailers with
electric brakes.
{WARNING:
Connecting a trailer that is not compatible with the
ITBC system may result in reduced or complete
loss of trailer braking. There may be an increase
in stopping distance or trailer instability which
could result in personal injury or damage to the
vehicle, trailer, or other property. An aftermarket
controller may be available for use with trailers
with surge, air or electric‐over‐hydraulic trailer
brake systems. To determine the type of brakes
on the trailer and the availability of controllers,
check with your trailer manufacturer or dealer.When trailering, make sure of the following:
.The ITBC system is used only with trailers that are
equipped with electric brakes.
.All applicable local and federal laws and
regulations are followed.
.All electrical and mechanical connections to the
trailer are made correctly.
.The trailer
’s brakes are in proper working
condition.
.The trailer and vehicle are properly loaded for the
towing condition.
The ITBC system is a factory installed item.
Out‐of‐factory installation of this system should
not be attempted. GM is not responsible for warranty or
performance of the system resulting from out‐of‐factory
installation.
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Manual Trailer Brake Apply
The Manual Trailer Brake Apply Lever is located on the
Trailer Brake Control Panel and is used to apply the
trailer’s electric brakes independent of the vehicle’ s
brakes. This lever is used in the Trailer Gain Adjustment
Procedure to properly adjust the power output to the
trailer brakes. Sliding the lever to the left will apply only
the trailer brakes. The power output to the trailer is
indicated in the Trailer Brake Display Page in the DIC.
If the vehicle’s service brakes are applied while using
the Manual Trailer Brake Apply Lever, the trailer output
power will be the greater of the two.
The trailer and the vehicle's brake lamps will come on
when either vehicle braking or manual trailer brakes are
applied.
Trailer Gain Adjustment Procedure
Trailer Gain should be set for a specific trailering
condition and must be adjusted any time vehicle
loading, trailer loading or road surface conditions
change.
Setting the Trailer Gain properly is needed for the
best trailer stopping performance. A trailer that is
over-gained may result in locked trailer brakes. A trailer
that is under-gained may result in not enough trailer
braking. Both of these conditions may result in poorer
stopping and stability of the vehicle and trailer. Use the following procedure to correctly adjust Trailer
Gain for each towing condition:
1. Make sure the trailer brakes are in proper working condition.
2. Connect a properly loaded trailer to the vehicle and make all necessary mechanical and electrical
connections. See Loading the Vehicle
on
page 5‑31for more information.
3. After the electrical connection is made to a trailer equipped with electric brakes:
.A TRAILER CONNECTED message will be
briefly displayed on the DIC display.
.The Trailer Brake Display Page will appear
on the DIC showing TRAILER GAIN and
TRAILER OUTPUT.
.In the Trailer Output display on the DIC,
“- - - - - -“ will disappear if there is no error
present. Connecting a trailer without electric
brakes will not clear the six dashed lines.
4. Adjust the Trailer Gain by using the gain adjustment (+ / -) buttons on the Trailer Brake
Control Panel.
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5. Drive the vehicle with the trailer attached on alevel road surface representative of the towing
condition and free of traffic at about 20 to 25 mph
(32 to 40 km/h) and fully apply the Manual Trailer
Brake Apply lever.
Adjusting trailer gain at speeds lower than
20 to 25 mph (32 to 40 km/h) may result in an
incorrect gain setting.
6. Adjust the Trailer Gain to just below the point of trailer wheel lock-up, indicated by trailer wheel
squeal or tire smoke when a trailer wheel locks.
Trailer wheel lock-up may not occur if towing a
heavily loaded trailer. In this case, adjust the
Trailer Gain to the highest allowable setting for
the towing condition.
7. Re-adjust Trailer Gain any time vehicle loading, trailer loading or road surface conditions change or
if trailer wheel lock-up is noticed at any time while
towingOther ITBC Related DIC Messages
In addition to displaying TRAILER GAIN and TRAILER
OUTPUT through the DIC, trailer connection and ITBC
system status is displayed in the DIC.
TRAILER CONNECTED –This message will be
briefly displayed when a trailer with electric brakes
is first connected to the vehicle. This message will
automatically turn off in about ten seconds. The driver
can also acknowledge this message before it
automatically turns off.
CHECK TRAILER WIRING –This message will be
displayed if:
1. The ITBC system first determines connection to a trailer with electric brakes and then the trailer
harness becomes disconnected from the vehicle.
If the disconnect occurs while the vehicle is
stationary, this message will automatically turn off
in about thirty seconds. This message will also turn
off if the driver acknowledges this message off or if
the trailer harness is re-connected.
If the disconnect occurs while the vehicle is
moving, this message will continue until the ignition
is turned off. This message will also turn off if the
driver acknowledges this message off or if the
trailer harness is re-connected.
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Driving with a Trailer
{WARNING:
When towing a trailer, exhaust gases may collect
at the rear of the vehicle and enter if the liftgate,
trunk/hatch, or rear-most window is open.
Engine exhaust contains carbon monoxide (CO)
which cannot be seen or smelled. It can cause
unconsciousness and even death.
To maximize safety when towing a trailer:
.Have the exhaust system inspected for leaks
and make necessary repairs before starting
a trip.
.Never drive with the liftgate, trunk/hatch,
or rear-most window open.
.Fully open the air outlets on or under the
instrument panel.
.Adjust the Climate Control system to a setting
that brings in only outside air and set the fan
speed to the highest setting. See Climate
Control System in the Index.
For more information about carbon monoxide, see
Engine Exhaust on page 3‑52. Towing a trailer requires a certain amount of
experience. The combination you are driving is
longer and not as responsive as the vehicle itself.
Get acquainted with the handling and braking of the
rig before setting out for the open road.
Before starting, check all trailer hitch parts and
attachments, safety chains, electrical connectors,
lamps, tires and mirrors. If the trailer has electric
brakes, start the combination moving and then apply
the trailer brake controller by hand to be sure the
brakes work.
During the trip, check occasionally to be sure that the
load is secure and the lamps and any trailer brakes
still work.
Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving the vehicle without a trailer.
This can help to avoid heavy braking and sudden turns.
Passing
More passing distance is needed when towing a trailer.
The combination will not accelerate as quickly and is
longer so it is necessary to go much farther beyond the
passed vehicle before returning to the lane.
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