2007 GMC YUKON tow

Electric Brake Control Wiring
Provisions
These wiring provisions are included with your
vehicle as part of the heavy-duty trailer wiring
package. These provisions are for an electric
brake controller. The red/black stripe power feed
will not be connected to the battery until the
ring terminal is unstowed and connected to the
underhood electrical center. The instrument panel
contains blunt cut wires near the data link
connector for the trailer brake controller. The
harness contains the following wires:
Dark Blue: Brake Signal to Trailer Connector
Red/Black: Battery
Light Blue/White: Brake Switch
White: Ground
It should be installed by your dealer or a qualied
service center.
Trailer Recommendations
You must subtract your hitch loads from the Cargo
Weight Rating (CWR). CWR is the maximum
weight of the load your vehicle can carry. It doesn’t
include the weight of the people inside, but you
can gure about 150 lbs. (68 kg) for each
seat. The total cargo load must not be more than
your vehicles CWR.
Weigh your vehicle with your trailer attached, so
that you won’t go over the GVWR or GAWR. If you
are using a weight-distributing hitch, weigh the
vehicle without the spring bars in place.
You’ll get the best performance if you spread out
the weight of your load the right way, and if
you choose the correct hitch and trailer brakes.
For more information seeTowing a Trailer
on page 400.
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Engine Oil
If the ENGINE OIL LOW ADD OIL message
appears on the Driver Information Center (DIC),
it means you need to check your engine oil
level right away. For more information, see
ENGINE OIL LOW ADD OIL underDIC Warnings
and Messages on page 252.
You should check your engine oil level regularly;
this is an added reminder.
Checking Engine Oil
It is a good idea to check your engine oil every
time you get fuel. In order to get an accurate
reading, the oil must be warm and the vehicle must
be on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 430
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several
minutes to drain back into the oil pan. If you
do not do this, the oil dipstick might not
show the actual level.
2. Pull out the dipstick and clean it with a paper
towel or cloth, then push it back in all the
way. Remove it again, keeping the tip down,
and check the level.
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5. Inspect or replace the engine air cleaner/lter.
6. Reinstall the cover and tighten the screws.
7. Reset the air lter restriction indicator, if
the vehicle has one, by pressing the top button
on the indicator.
{CAUTION:
Operating the engine with the air
cleaner/lter off can cause you or others
to be burned. The air cleaner not only
cleans the air; it helps to stop ames if
the engine backres. If it is not there and
the engine backres, you could be
burned. Do not drive with it off, and be
careful working on the engine with the air
cleaner/lter off.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the
transmission uid level. A transmission uid leak
is the only reason for uid loss. If you suspect
a small leak, then use the following checking
procedures to check the uid level. However, if
there is a large leak, then it may be necessary to
have the vehicle towed to a dealership service
department and have it repaired before driving the
vehicle further.
Notice:Use of the incorrect automatic
transmission uid may damage your vehicle,
and the damages may not be covered by
your warranty. Always use the automatic
transmission uid listed inRecommended
Fluids and Lubricants on page 561.
Change the uid and lter at the intervals listed in
the Maintenance Schedule. SeeScheduled
Maintenance on page 551. Be sure to use the
transmission uid listed inRecommended Fluids
and Lubricants on page 561.
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Cold Check Procedure
Use this procedure only as a reference to
determine if the transmission has enough uid to
be operated safely until a hot check procedure
can be made. The hot check procedure is the most
accurate method to check the uid level. Perform
the hot check procedure at the rst opportunity.
Use this cold check procedure to check uid level
when the transmission temperature is between
80°F and 90°F (27°C and 32°C).
1. Locate the transmission dipstick at the rear of
the engine compartment, on the passenger’s
side of the vehicle.The dipstick handle has
this graphic. SeeEngine
Compartment Overview
on page 430for
more information.
2. Flip the handle up, and then pull out the
dipstick and wipe it with a clean rag or
paper towel.
3. Install the dipstick by pushing it back in all the
way, wait three seconds, and then pull it back
out again.
4. Check both sides of the dipstick, and read the
lower level. Repeat the check procedure to
verify the reading.
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5. If the uid level is below the COLD check
band, add only enough uid as necessary
to bring the level into the COLD band. It does
not take much uid, generally less than
one pint (0.5L). Do not overll.
6. Perform a hot check at the rst opportunity
after the transmission reaches a normal
operating temperature between 160°F to
200°F (71°C to 93°C).
7. If the uid level is in the acceptable range,
push the dipstick back in all the way, then
ip the handle down to lock the dipstick
in place.
Hot Check Procedure
Use this procedure to check the transmission uid
level when the transmission uid temperature is
between 160°F and 200°F (71°C and 93°C).
The hot check is the most accurate method to
check the uid level. The hot check should be
performed at the rst opportunity in order to verify
the cold check. The uid level rises as uid
temperature increases, so it is important to ensure
the transmission temperature is within range.
1. Locate the transmission dipstick at the rear of
the engine compartment, on the passenger’s
side of the vehicle.
The dipstick handle has
this graphic. SeeEngine
Compartment Overview
on page 430for
more information.
2. Flip the handle up, and then pull out the
dipstick and wipe it with a clean rag or
paper towel.
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Notice:If your engine catches re because
you keep driving with no coolant, your vehicle
can be badly damaged. The costly repairs
would not be covered by your warranty.
SeeOverheated Engine Protection Operating
Mode on page 450for information on driving
to a safe place in an emergency.
If No Steam Is Coming From Your
Engine
The ENGINE OVERHEATED STOP ENGINE
or the ENGINE OVERHEATED IDLE ENGINE
message, along with a low coolant condition,
can indicate a serious problem.
If you get an engine overheat warning, but see or
hear no steam, the problem may not be too
serious. Sometimes the engine can get a little too
hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. SeeTowing a Trailer
on page 400.If you get the ENGINE OVERHEATED STOP
ENGINE or the ENGINE OVERHEATED IDLE
ENGINE message with no sign of steam, try this
for a minute or so:
1. If you have an air conditioner and it is on,
turn it off.
2. Turn on your heater to full hot at the highest
fan speed and open the windows as
necessary.
3. In heavy traffic, let the engine idle in
NEUTRAL (N) while stopped. If it is safe to
do so, pull off the road, shift to PARK (P)
or NEUTRAL (N) and let the engine idle.
If you no longer have the overheat warning,
you can drive. Just to be safe, drive slower for
about 10 minutes. If the warning does not
come back on, you can drive normally.
If the warning continues, pull over, stop, and
park your vehicle immediately.
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If there is still no sign of steam and your vehicle
is equipped with an engine-driven cooling fan,
push down the accelerator until the engine speed
is about twice as fast as normal idle speed for
at least ve minutes while you are parked.
If there is still no sign of steam and your vehicle is
equipped with an electric cooling fan, idle the
engine for ve minutes while you are parked.
If you still have the warning, turn off the engine
and get everyone out of the vehicle until it
cools down. Also, see “Overheated Engine
Protection Operating Mode” later in this section.
You may decide not to lift the hood but to get
service help right away.Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is
displayed, an overheat protection mode which
alternates ring groups of cylinders helps prevent
engine damage. In this mode, you will notice a
loss in power and engine performance. This
operating mode allows your vehicle to be driven to
a safe place in an emergency. Driving extended
miles (km) and/or towing a trailer in the overheat
protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine
damage, allow the engine to cool before
attempting any repair. The engine oil will be
severely degraded. Repair the cause of coolant
loss, change the oil and reset the oil life
system. SeeEngine Oil on page 432.
450

4. With the coolant surge tank pressure cap off,
start the engine and let it run until you can
feel the upper radiator hose getting hot. Watch
out for the engine cooling fan.
By this time, the coolant level inside the
coolant surge tank may be lower. If the level is
lower, add more of the proper mixture to the
coolant surge tank until the level reaches
the FULL COLD mark.5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
6. Verify coolant level after engine is shut off
and the coolant is cold. If necessary, repeat
coolant ll procedure steps 1 through 6.
Engine Fan Noise
Your vehicle has electric cooling fans, you may
hear the fans spinning at low speed during
most everyday driving. The fans may turn off if no
cooling is required. Under heavy vehicle loading,
trailer towing, and/or high outside temperatures, or
if you are operating your air conditioning system,
the fans may change to high speed and you
may hear an increase in fan noise. This is normal
and indicates that the cooling system is
functioning properly. The fans will change to low
speed when additional cooling is no longer
required.
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