Section 7 GMC SIERRA 2010 Workshop Manual

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.
Fifth Wheel and Gooseneck Trailering
Fifth wheel and gooseneck trailers can be used
with many pickup models. These trailers place a
larger percentage of the weight (kingpin weight) on the
tow vehicle than conventional trailers. Make sure this
weight does not cause the vehicle to exceed GAWR
or GVWR.
Fifth wheel or gooseneck kingpin weight should be
15 to 25 percent of the trailer weight up to the maximum
amount specified in the trailering chart for the vehicle.
See “Weight of the Trailer” in this section for more
information.
The hitch should be located in the pickup bed so that
its centerline is over or slightly in front of the rear axle.
Take care that it is not so far forward that it will contact
the back of the cab in sharp turns. This is especially
important for short box pickups. Trailer pin box
extensions and sliding fifth wheel hitch assemblies can
help this condition. There should be at least six inches
of clearance between the top of the pickup box and the
bottom of the trailer shelf that extends over the box.
Make sure the hitch is attached to the tow vehicle frame
rails. Do not use the pickup box for support.
5-62

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.
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 3‑34for 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” later 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
5-63

All DIC warning and service messages must first
be acknowledged by the driver by pressing the
odometer trip stem or the DIC Vehicle Information
button (if equipped) before the Trailer Brake Display
Page can be displayed and Trailer Gain can be
adjusted.
TRAILER GAIN–This setting is displayed anytime the
Trailer Brake Display Page is active. This setting can be
adjusted from 0.0 to 10.0 with either a trailer connected
or disconnected. To adjust the Trailer Gain, press one of
the Trailer Gain adjustment buttons located on the
Trailer Brake Control Panel. Press and hold a gain
button to cause the Trailer Gain to continuously adjust.
To turn the output to the trailer off, adjust the Trailer
Gain setting to 0.0 (zero).
0.0 (zero) gain is the factory default setting. To properly
adjust trailer gain, see the Trailer Gain Adjustment
Procedure later in this section. TRAILER OUTPUT
–This is displayed any time a trailer
with electric brakes is connected. Output to the electric
brakes is based on the amount of vehicle braking
present and relative to the Trailer Gain setting. Output is
displayed from 0 to 10 bars for each gain setting.
The Trailer Output will indicate “- - - - - -“on the Trailer
Brake Display Page whenever the following occur:
.No trailer is connected.
.A trailer without electric brakes is connected
(no DIC message is displayed).
.A trailer with electric brakes has become
disconnected (a CHECK TRAILER WIRING
message will also be displayed on the DIC).
.There is a fault present in the wiring to the electric
trailer brakes (a CHECK TRAILER WIRING
message will also be displayed on the DIC).
.There is a fault in the ITBC system (a SERVICE
TRAILER BRAKE SYSTEM message will also be
displayed in the DIC).
5-67

If the vehicle is equipped with the“Heavy-Duty
Trailering” option, please refer to “Heavy-Duty Trailer
Wiring Package” earlier in this section.
When the camper-wiring harness is ordered without the
heavy-duty trailering package, an eight-wire harness
with a seven-pin connector is located at the rear of the
vehicle and is tied to the vehicle's frame.
Electric Brake Control Wiring
Provisions
These wiring provisions are included with the vehicle as
part of the trailer wiring package. These provisions are
for an electric brake controller. The instrument panel
contains blunt cut wires behind the steering column 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/retailer or a
qualified service center.
If the vehicle is equipped with an ITBC, the blunt cuts
exist, but are not connected further in the harness. If an
aftermarket trailer brake controller is installed, the ITBC
must be disconnected. Do not power both ITBC and
aftermarket controllers to control the trailer brakes at the
same time.
5-76

Section 6 Service and Appearance Care
Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Accessories and Modifications . . . . . . . . . . . . . . . . . . 6-4
California Proposition 65 Warning . . . . . . . . . . . . . . . 6-5
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Doing Your Own Service Work . . . . . . . . . . . . . . . . . . 6-5
Adding Equipment to the Outside of the Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Gasoline Octane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Gasoline Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
California Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Fuel E85 (85% Ethanol) . . . . . . . . . . . . . . . . . . . . . . . . . 6-9
Fuels in Foreign Countries . . . . . . . . . . . . . . . . . . . . . 6-11
Filling the Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
Filling a Portable Fuel Container . . . . . . . . . . . . . . . 6-13 Checking Things Under the Hood
. . . . . . . . . . . . . . .6-14
Hood Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15
Engine Compartment Overview . . . . . . . . . . . . . . . . 6-16
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-18
Engine Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 6-20
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . . 6-21
Automatic Transmission Fluid (4-Speed Transmission) . . . . . . . . . . . . . . . . . . . . . 6-23
Automatic Transmission Fluid (6-Speed Transmission) . . . . . . . . . . . . . . . . . . . . . 6-26
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-30
Engine Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-31
Engine Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-34
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-36
Engine Fan Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-37
Power Steering Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 6-37
Windshield Washer Fluid . . . . . . . . . . . . . . . . . . . . . . 6-38
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-39
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-43
Jump Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-44
6-1

Section 6 Service and Appearance Care
Rear Axle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-50
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-52
Noise Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53
Tampering with Noise Control
System Prohibited . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53
Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-57
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-57
Headlamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-57
Center High-Mounted Stoplamp (CHMSL) and Cargo Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58
Pickup Box Identification and Fender Marker Lamps . . . . . . . . . . . . . . . . . . 6-59
Taillamps, Turn Signal, Stoplamps and Back-up Lamps . . . . . . . . . . . . . . . . . . . . . . . . 6-60
License Plate Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62
Replacement Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62
Windshield Wiper Blade Replacement . . . . . . . . . . .6-63Tires
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-64
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . . . . . . . . . 6-65
Tire Terminology and Definitions . . . . . . . . . . . . . . . 6-70
Inflation - Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . 6-72
High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . . 6-74
Dual Tire Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-74
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . 6-75
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . 6-76
Tire Inspection and Rotation . . . . . . . . . . . . . . . . . . . 6-80
When It Is Time for New Tires . . . . . . . . . . . . . . . . . 6-82
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-83
Different Size Tires and Wheels . . . . . . . . . . . . . . . 6-85
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . 6-85
Wheel Alignment and Tire Balance . . . . . . . . . . . . 6-87
Wheel Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-87
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
Changing a Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-90
Removing the Spare Tire and Tools . . . . . . . . . . . . 6-92
Removing the Flat Tire and Installing the Spare Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-97
Secondary Latch System . . . . . . . . . . . . . . . . . . . . . 6-103
Storing a Flat or Spare Tire and Tools . . . . . . . . 6-106
Spare Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-109
6-2

Section 6 Service and Appearance Care
Appearance Care. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-110
Interior Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-110
Fabric/Carpet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-111
Leather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-112
Instrument Panel, Vinyl, and Other Plastic Surfaces . . . . . . . . . . . . . . . . 6-112
Care of Safety Belts . . . . . . . . . . . . . . . . . . . . . . . . . . 6-112
Weatherstrips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-113
Washing Your Vehicle . . . . . . . . . . . . . . . . . . . . . . . . 6-113
Cleaning Exterior Lamps/Lenses . . . . . . . . . . . . . 6-113
Finish Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-114
Windshield and Wiper Blades . . . . . . . . . . . . . . . . . 6-114
Aluminum or Chrome-Plated Wheels and Trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-115
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-116
Sheet Metal Damage . . . . . . . . . . . . . . . . . . . . . . . . . 6-116
Finish Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-116
Underbody Maintenance . . . . . . . . . . . . . . . . . . . . . . 6-116
Chemical Paint Spotting . . . . . . . . . . . . . . . . . . . . . . 6-116 Vehicle Identification
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-117
Vehicle Identification Number (VIN) . . . . . . . . . . . 6-117
Service Parts Identification Label . . . . . . . . . . . . . 6-117
Electrical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-117
Add-On Electrical Equipment . . . . . . . . . . . . . . . . . 6-117
Windshield Wiper Fuses . . . . . . . . . . . . . . . . . . . . . . 6-118
Power Windows and Other Power Options . . . 6-118
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . . 6-118
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . 6-119
Center Instrument Panel Fuse Block . . . . . . . . . 6-121
Underhood Fuse Block . . . . . . . . . . . . . . . . . . . . . . . 6-122
Capacities and Specifications . . . . . . . . . . . . . . . . . .6-126
6-3

Engine Compartment Overview
If the vehicle has a diesel engine and/or an Allison Transmission, see the maintenance schedule section in the
DURAMAX®Diesel manual.
5.3 L V8 Engine (4.3 L V6 Engine, 4.8 L V6 Engine, 6.0 L V8 Engine and 6.2 L V8 Engine similar)
6-16

Engine Oil
For diesel engine vehicles, see“Engine Oil”in the
DURAMAX®Diesel manual.
Checking Engine Oil
It is a good idea to check the engine oil level at each
fuel fill. 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. See
Engine Compartment Overview
on page 6‑16for 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 this is not done, 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.
When to Add Engine Oil
If the oil is below the cross-hatched area at the tip
of the dipstick, add at least one liter/quart of the
recommended oil. This section explains what kind
of oil to use. For engine oil crankcase capacity, see
Capacities and Specifications on page 6‑126.
Notice: Do not add too much oil. If the engine
has so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, the engine could be damaged.
6-18

How to Add Automatic Transmission
Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid to use. SeeRecommended
Fluids and Lubricants on page 7‑12.
Using a funnel, add fluid down the transmission dipstick
tube only after checking the transmission fluid while it is
hot. A cold check is used only as a reference. If the fluid
level is low, add only enough of the proper fluid to bring
the level up to the HOT area for a hot check. It does
not take much fluid, generally less than 0.5 Liter (1 Pint).
Do not overfill.
Notice: Use of the incorrect automatic transmission
fluid may damage the vehicle, and the damages may
not be covered by the vehicle's warranty. Always
use the automatic transmission fluid listed in
Recommended Fluids and Lubricants on page 7‑12.
.After adding fluid, recheck the fluid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
.When the correct fluid level is obtained, push the
dipstick back in all the way; then flip the handle
down to lock the dipstick in place.
Automatic Transmission Fluid
(6-Speed Transmission)
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the transmission
fluid level. The only reason for fluid loss is a
transmission leak or overheating the transmission.
If you suspect a small leak, then use the following
checking procedures to check the fluid level. However,
if there is a large leak, then it may be necessary to have
the vehicle towed to a dealer/retailer service department
and have it repaired before driving the vehicle further.
Notice:Use of the incorrect automatic transmission
fluid may damage the vehicle, and the damages may
not be covered by the vehicle's warranty. Always
use the automatic transmission fluid listed in
Recommended Fluids and Lubricants on page 7‑12.
Change the fluid and filter at the intervals listed in the
Maintenance Schedule. See Scheduled Maintenance
on page 7‑3. Be sure to use the transmission fluid
listed in Recommended Fluids and Lubricantson
page 7‑12.
6-26