2010 GMC YUKON XL trailer

Automatic Transmission Fluid
(4-Speed Transmission)
When to Check and Change Automatic
Transmission Fluid
A good time to check the automatic transmission fluid
level is when the engine oil is changed.
Change the fluid and filter at the intervals listed in
Scheduled Maintenance
on page 7‑3and be sure
to use the transmission fluid listed in Recommended
Fluids and Lubricants on page 7‑11.
How to Check Automatic Transmission
Fluid
Because this operation can be a little difficult, you
may choose to have this done at the dealer service
department.
If you do it yourself, be sure to follow all the instructions
here or you could get a false reading on the dipstick.
Notice: Too much or too little fluid can damage the
transmission. Too much can mean that some of the
fluid could come out and fall on hot engine parts or
exhaust system parts, starting a fire. Too little fluid
could cause the transmission to overheat. Be sure
to get an accurate reading if checking the
transmission fluid. Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:
.When outside temperatures are above
32°C (90°F).
.At high speed for quite a while.
.In heavy traffic
—especially in hot weather.
.While pulling a trailer.
To get the right reading, the fluid should be at normal
operating temperature, which is 82°C to 93°C
(180°F to 200°F).
Get the vehicle warmed up by driving about
24 km (15 miles) when outside temperatures are above
10°C (50°F). If it is colder than 10°C (50°F), drive the
vehicle in 3 (Third) until the engine temperature gauge
moves and then remains steady for 10 minutes.
A cold fluid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine
run at idle for five minutes if outside temperatures are
10°C (50°F) or more. If it is colder than 10°C (50°F),
you may have to idle the engine longer. Should the fluid
level be low during this cold check, you must check the
fluid hot before adding fluid. Checking the fluid hot will
give you a more accurate reading of the fluid level.
6-24

If No Steam Is Coming From The
Engine Compartment
The ENGINE OVERHEATED STOP ENGINE or the
ENGINE OVERHEATED IDLE ENGINE message, along
with a low coolant condition, can indicate a serious
problem.
If an engine overheat warning is displayed but no steam
can be seen or heard, the problem may not be too
serious. Sometimes the engine can get a little too hot
when the vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.
.Idles for long periods in traffic.
.Tows a trailer. SeeTowing a Trailer on page 5‑49.
If the overheat warning is displayed with no sign of
steam: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest fan speed. Open the windows as
necessary. 3. In heavy traffic, let the engine idle in N (Neutral)
while stopped. If it is safe to do so, pull off the
road, shift to P (Park) or N (Neutral) and let the
engine idle.
If the temperature overheat gauge is no longer in
the overheat zone or an overheat warning no longer
displays, the vehicle can be driven. Continue to drive
the vehicle slow for about 10 minutes. Keep a safe
vehicle distance from the car in front of you. If the
warning does not come back on, continue to drive
normally.
If the warning continues, pull over, stop, and park the
vehicle right away.
If there is no sign of steam, idle the engine for
three minutes while parked. If the warning is still
displayed, turn off the engine until it cools down.
Also, see “Overheated Engine Protection Operating
Mode” later in this section.
6-38

Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
ENGINE POWER IS REDUCED message is displayed,
an overheat protection mode which alternates firing
groups of cylinders helps prevent engine damage.
In this mode, you will notice a loss in power and engine
performance. This operating mode allows the 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. See Engine Oil
on
page 6‑18.
Engine Fan Noise
If the vehicle has a clutched engine cooling fan, when
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing, and/or high outside temperatures, the fan speed
increases as the clutch more fully engages, so you may
hear an increase in fan noise. This is normal and should
not be mistaken as the transmission slipping or making
extra shifts. It is merely the cooling system functioning
properly. The fan will slow down when additional cooling
is not required and the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
If the 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 the 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.
6-39

Underhood Fuse Block
The underhood fuse block is located in the engine
compartment, on the driver side of the vehicle.
Lift the cover for access to the fuse/relay block.
If the vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
Notice:Spilling liquid on any electrical components
on the vehicle may damage it. Always keep the
covers on any electrical component.
To remove fuses, hold the end of the fuse between your
thumb and index finger and pull straight out.
Fuses Usage
1 Right Trailer Stop/Turn Lamp
2Electronic Stability Suspension
Control, Automatic Level Control
Exhaust
3 Left Trailer Stop/Turn Lamp
4 Engine Controls
6-122

FusesUsage
5Engine Control Module,
Throttle Control
6 Trailer Brake Controller
7 Front Washer
8 Oxygen Sensors
9 Antilock Brakes System 2
10 Trailer Back-up Lamps 11 Driver Side Low-Beam Headlamp
12 Engine Control Module (Battery)
13 Fuel Injectors, Ignition Coils
(Right Side)
14 Transmission Control Module
(Battery)
15 Vehicle Back-up Lamps
16 Passenger Side Low-Beam Headlamp
17 Air Conditioning Compressor
18 Oxygen Sensors
Fuses Usage
19 Transmission Controls (Ignition)
20 Fuel Pump
21 Fuel System Control Module
22 Headlamp Washer
23 Rear Windshield Washer
24Fuel Injectors, Ignition Coils
(Left Side)
25 Trailer Park Lamps
26 Driver Side Park Lamps
27 Passenger Side Park Lamps
28 Fog Lamps
29 Horn
30 Passenger Side High-Beam
Headlamp
31 Daytime Running Lamps (DRL)
32 Driver Side High-Beam Headlamp
33 Daytime Running Lamps 2
6-123

J-Case FusesUsage
57 Cooling Fan 1
58 Automatic Level Control Compressor
59 Heavy Duty Antilock Braking System
60 Cooling Fan 2
61 Antilock Brake System 1
62 Starter
63 Stud 2 (Trailer Brakes)
64 Left Bussed Electrical Center 1
65 Electric Running Boards
66 Heated Windshield Washer System
67 Transfer Case
68Stud 1 (Trailer Connector Battery
Power)
69 Mid-Bussed Electrical Center 1
70 Climate Control Blower
71 Power Liftgate Module
72 Left Bussed Electrical Center 2
Relays Usage
FAN HI Cooling Fan High Speed
FAN LO Cooling Fan Low Speed
FAN CNTRL Cooling Fan Control
HDLP LO/HID Low-Beam Headlamp
FOG LAMP Front Fog Lamps
A/C CMPRSR Air Conditioning Compressor
STRTR Starter
PWR/TRN Powertrain
FUEL PMP Fuel Pump
PRK LAMP Parking Lamps
REAR DEFOG Rear Defogger
RUN/CRANK Switched Power
6-125

.Automatic transmission shiftlock control system
check. SeeOwner Checks and Serviceson
page 7‑9.
.Ignition transmission lock check. See Owner
Checks and Services on page 7‑9.
.Hood and liftgate gas strut support service.
Visually inspect gas strut for signs of wear,
corrosion, cracks, loss of lubricant, or other
damage. Check the hold open ability of gas strut.
Replace as necessary with genuine parts from
your dealer.
.Engine cooling system and pressure cap pressure
check. Radiator and air conditioning condenser
outside cleaning. See Cooling System
on
page 6‑30.
.Exhaust system and nearby heat shields
inspection for loose or damaged components.
.Accelerator pedal check for damage, high effort,
or binding. Replace if needed.
First Engine Oil Change After Every
40 000 km/25,000 Miles
.Fuel system inspection for damage or leaks.
First Engine Oil Change After Every
80 000 km/50,000 Miles
.Engine air cleaner filter replacement. See Engine
Air Cleaner/Filter on page 6‑22.
.Automatic transmission fluid change (severe
service) for vehicles with Gross Vehicle Weight
Rating (GVWR) over 3 901 kg (8,600 lbs) or mainly
driven in heavy city traffic in hot weather, in hilly
or mountainous terrain, when frequently towing a
trailer, or used for taxi, police, or delivery service.
See Automatic Transmission Fluid (4-Speed
Transmission)
on page 6‑24or Automatic
Transmission Fluid (6-Speed Transmission)on
page 6‑27.
.Four‐wheel drive only: Transfer case fluid change
(severe service) for vehicles mainly driven when
frequently towing a trailer, or used for taxi, police,
or delivery service. Check vent hose at transfer
case for kinks and proper installation. Check to
be sure vent hose is unobstructed, clear, and free
of debris. During any maintenance, if a power
washer is used to clean mud and dirt from the
underbody, care should be taken to not directly
spray the transfer case output seals. High pressure
water can overcome the seals and contaminate
the transfer case fluid. Contaminated fluid will
decrease the life of the transfer case and should
be replaced.
7-6

I
Ignition Positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28
Infants and Young Children, Restraints . . . . . . . . . . . . 2-59
Inflation - Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-72
Instrument PanelBrightness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Instrument Panel Cluster . . . . . . . . . . . . . . . . . . . . . . . . . . 4-30
Integrated Trailer Brake Control System (ITBC) . . . . 5-49
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-2
J
Jump Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-46
K
Keyless Entry
Remote (RKE) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Keyless Entry System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
L
Labeling, Tire Sidewall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-64
Lamps Auxiliary Roof Mounted Lamp . . . . . . . . . . . . . . . . . . . . 4-13
Daytime Running (DRL) . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Dome Lamp Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
License Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60
Malfunction Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-39
Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-54
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-46
LATCH System for Child Restraints . . . . . . . . . . . . . . . . 2-67
Level Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-48
Liftgate, Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
Liftgate/Liftglass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
Liftglass/Liftgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
Lighting
Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
i - 8