ECO mode GMC SIERRA 2008 Service Manual

To remove the fuel cap, turn it slowly counterclockwise.
{CAUTION:
Fuel can spray out on you if you open the fuel
cap too quickly. If you spill fuel and then
something ignites it, you could be badly
burned. This spray can happen if your tank is
nearly full, and is more likely in hot weather.
Open the fuel cap slowly and wait for any
hiss noise to stop. Then unscrew the cap all
the way.
If your vehicle is a dual fuel tank chassis cab model,
and it runs out of fuel, refuel the front fuel tank rst to
ensure a quick restart.
Be careful not to spill fuel. Do not top off or overll the
tank and wait a few seconds after you have nished
pumping before removing the nozzle. Clean fuel
from painted surfaces as soon as possible. See
Washing Your Vehicle on page 5-116.
When replacing the fuel cap, turn it clockwise until it
clicks. It will require more effort to turn the fuel cap on
the last turn as you tighten it. Make sure the cap is
fully installed. The diagnostic system can determine ifthe fuel cap has been left off or improperly installed.
This would allow fuel to evaporate into the atmosphere.
SeeMalfunction Indicator Lamp on page 3-48.
The TIGHTEN GAS CAP message will be displayed on
the Driver Information Center (DIC) if the fuel cap is
not properly installed. SeeDIC Warnings and Messages
on page 3-63for more information.
{CAUTION:
If a re starts while you are refueling, do not
remove the nozzle. Shut off the ow of fuel by
shutting off the pump or by notifying the
station attendant. Leave the area immediately.
Notice:If you need a new fuel cap, be sure to get
the right type. Your dealer/retailer can get one
for you. If you get the wrong type, it may not t
properly. This may cause your malfunction indicator
lamp to light and may damage your fuel tank and
emissions system. SeeMalfunction Indicator Lamp
on page 3-48.
5-11

GAWR RR:Gross Axle Weight Rating for the rear
axle. SeeLoading Your Vehicle on page 4-36.
Intended Outboard Sidewall
:The side of
an asymmetrical tire, that must always face
outward when mounted on a vehicle.
Kilopascal (kPa)
:The metric unit for air pressure.
Light Truck (LT-Metric) Tire
:A tire used on
light duty trucks and some multipurpose passenger
vehicles.
Load Index
:An assigned number ranging from
1 to 279 that corresponds to the load carrying
capacity of a tire.
Maximum Ination Pressure
:The maximum air
pressure to which a cold tire can be inated.
The maximum air pressure is molded onto the
sidewall.
Maximum Load Rating
:The load rating for a tire
at the maximum permissible ination pressure for
that tire.
Maximum Loaded Vehicle Weight
:The sum of
curb weight, accessory weight, vehicle capacity
weight, and production options weight.Normal Occupant Weight
:The number of
occupants a vehicle is designed to seat multiplied
by 150 lbs (68 kg). SeeLoading Your Vehicle
on page 4-36.
Occupant Distribution
:Designated seating
positions.
Outward Facing Sidewall
:The side of an
asymmetrical tire that has a particular side that
faces outward when mounted on a vehicle.
The side of the tire that contains a whitewall, bears
white lettering, or bears manufacturer, brand,
and/or model name molding that is higher
or deeper than the same moldings on the other
sidewall of the tire.
Passenger (P-Metric) Tire
:A tire used on
passenger cars and some light duty trucks and
multipurpose vehicles.
Recommended Ination Pressure
:Vehicle
manufacturer’s recommended tire ination
pressure as shown on the tire placard. See
Inflation - Tire Pressure on page 5-74andLoading
Your Vehicle on page 4-36.
5-72

TPMS Sensor Matching Process
Each TPMS sensor has a unique identication code.
Any time you rotate your vehicle’s tires or replace one or
more of the TPMS sensors, the identication codes will
need to be matched to the new tire/wheel position. The
sensors are matched to the tire/wheel positions in the
following order: driver side front tire, passenger side front
tire, passenger side rear tire, and driver side rear tire
using a TPMS diagnostic tool. See your dealer/retailer
for service.
The TPMS sensors can also be matched to each
tire/wheel position by increasing or decreasing the tire’s
air pressure. If increasing the tire’s air pressure, do not
exceed the maximum ination pressure indicated on the
tire’s sidewall.
To decrease air-pressure out of a tire you can use the
pointed end of the valve cap, a pencil-style air pressure
gage, or a key.
You have two minutes to match the rst tire/wheel
position, and ve minutes overall to match all
four tire/wheel positions. If it takes longer than
two minutes, to match the rst tire and wheel, or more
than ve minutes to match all four tire and wheel
positions the matching process stops and you need to
start over.The TPMS sensor matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to ON/RUN with the
engine off.
3. Press the Remote Keyless Entry (RKE) transmitter’s
LOCK and UNLOCK buttons at the same time for
approximately ve seconds. The horn sounds twice
to signal the receiver is in relearn mode and TIRE
LEARNING ACTIVE message displays on the DIC
screen.
If your vehicle does not have RKE, press the Driver
Information Center (DIC) vehicle information
button until the PRESS
VTO RELEARN TIRE
POSITIONS message displays. The horn sounds
twice to signal the receiver is in relearn mode
and TIRE LEARNING ACTIVE message displays
on the DIC screen.
If your vehicle does not have RKE or DIC buttons,
press the trip odometer reset stem located on the
instrument panel cluster until the PRESS
VTO
RELEARN TIRE POSITIONS message displays.
The horn sounds twice to signal the receiver is in
relearn mode and TIRE LEARNING ACTIVE
message displays on the DIC screen.
5-80

For regular cab models, the equipment you will need is
behind the passenger’s seat. For extended and crew
cab models, the equipment is on the shelf behind the
passenger’s side second row seat.
1. Turn the knob on the jack counterclockwise to lower
the jack head to release the jack from its holder.
2. Remove the wheel blocks and the wheel block
retainer by turning the wing nut counterclockwise.
3. Remove the wing nut used to retain the storage
bag and tools by turning it counterclockwise.
You will use the jack handle extensions and the wheel
wrench to remove the underbody-mounted spare tire.
A. Spare Tire (Valve
Stem Pointed Down)
B. Hoist Assembly
C. Hoist Cable
D. Tire/Wheel Retainer
E. Hoist Shaft
F. Hoist End of
Extension ToolG. Hoist Shaft Access
Hole
H. Wheel Wrench
I. Jack Handle
Extensions
J. Spare Tire Lock
(If equipped)
1. Open the spare tire lock cover on the bumper and
use the ignition key to remove the spare tire lock (J).
To remove the spare tire lock, insert the ignition key
turn and pull straight out.
5-95

Trip Interruption Benets and Assistance:In the
event of a warranty related vehicle disablement,
while en route and over 150 miles (250 kilometres)
from original point of departure, you may qualify for
trip interruption expense assistance. This assistance
covers reasonable reimbursement of up to a
maximum of $500. In Canada, maximums include:
(A) meals (maximum of $50/day), (B) lodging
(maximum of $100/night) and (C) alternate ground
transportation (maximum of $40/day). This benet is
to assist you with some of the unplanned expense
you may incur while waiting for your vehicle to be
repaired.
Original detailed receipts, and a copy of the repair
order are required. In Canada, pre-authorization is
also required.
Once authorization has been given, your advisor will
help you make any necessary arrangements and
explain how to claim for trip interruption expense
assistance.
Alternative Service (Canada only):There may be
times, when Roadside Assistance cannot provide
timely assistance. Your advisor may authorize you to
secure local emergency road service, and you will be
reimbursed up to $100 (Canadian) upon submission
of the original receipt to Roadside Assistance.In many instances, mechanical failures may be covered.
However, when other services are utilized, our
Roadside Assistance Representatives will explain any
payment obligations you might incur.
GMC and General Motors of Canada Limited reserve
the right to limit services or reimbursement to an owner
or driver when, in their sole discretion, the claims
become excessive in frequency or type of occurrence.
Calling For Assistance
For prompt and efficient assistance when calling, please
provide the following to the Roadside Assistance
Representative:
Your name, home address, and home telephone
number
Telephone number of your location
Location of the vehicle.
Model, year, color, and license plate number
of the vehicle
Odometer reading, Vehicle Identication Number
(VIN), and delivery date of the vehicle
Description of the problem
7-8

Current and Past Model Order Forms
Technical Service Bulletins and Manuals are available
for current and past model GM vehicles. To request
an order form, specify year and model name of
the vehicle.
ORDER TOLL FREE: 1-800-551-4123
Monday-Friday 8:00 AM - 6:00 PM
Eastern Time
For Credit Card Orders Only
(VISA-MasterCard-Discover), visit Helm, Inc.
on the World Wide Web at: www.helminc.com
Or you can write to:
Helm, Incorporated
P.O. Box 07130
Detroit, MI 48207
Prices are subject to change without notice and without
incurring obligation. Allow ample time for delivery.
Note to Canadian Customers: All listed prices are
quoted in U.S. funds. Canadian residents are to make
checks payable in U.S. funds.
Vehicle Data Recording and
Privacy
Your GM vehicle has a number of sophisticated
computers that record information about the vehicle’s
performance and how it is driven. For example,
your vehicle uses computer modules to monitor and
control engine and transmission performance, to monitor
the conditions for airbag deployment and deploy
airbags in a crash and, if so equipped, to provide
antilock braking to help the driver control the vehicle.
These modules may store data to help your
dealer/retailer technician service your vehicle. Some
modules may also store data about how you operate the
vehicle, such as rate of fuel consumption or average
speed. These modules may also retain the owner’s
personal preferences, such as radio pre-sets, seat
positions, and temperature settings.
7-16

Electrical System (cont.)
Instrument Panel Fuse Block.......................5-124
Power Windows and Other Power Options....5-123
Underhood Fuse Block...............................5-126
Windshield Wiper Fuses.............................5-123
Engine
Air Cleaner/Filter.........................................5-19
Check and Service Engine Soon Light............3-48
Coolant......................................................5-28
Coolant Heater............................................2-26
Coolant Temperature Gage...........................3-46
Drive Belt Routing.......................................6-18
Engine Compartment Overview......................5-14
Exhaust.....................................................2-53
Fan Noise..................................................5-39
Fast Idle System.........................................2-25
Oil .............................................................5-15
Oil Life System...........................................5-18
Overheated Protection Operating Mode...........5-33
Overheating................................................5-30
Running While Parked..................................2-54
Starting......................................................2-24
Entry Lighting.................................................3-21
Event Data Recorders.....................................7-17
Exit Lighting...................................................3-21
Extender, Safety Belt.......................................1-35
Exterior Lamps...............................................3-17F
Fast Idle System............................................2-25
Filter
Engine Air Cleaner......................................5-19
Finish Damage.............................................5-119
Fixed Mast Antenna.......................................3-126
Flashers, Hazard Warning.................................. 3-8
Flash-to-Pass.................................................3-11
Flat Tire........................................................5-91
Flat Tire, Changing.........................................5-92
Flat Tire, Storing...........................................5-108
Fluid.....................................................5-22, 5-25
Power Steering...........................................5-39
Windshield Washer......................................5-40
Fog Lamp
Fog ...........................................................3-20
Fog Lamp Light..............................................3-52
Four-Wheel Drive....................................2-36, 5-52
Four-Wheel-Drive Light....................................3-53
Front Axle......................................................5-54
Fuel............................................................... 5-6
Additives...................................................... 5-7
California Fuel.............................................. 5-7
E85 (85% Ethanol)........................................ 5-8
Filling a Portable Fuel Container....................5-12
Filling the Tank...........................................5-10
5

Mirrors
Automatic Dimming Rearview with Compass
and Temperature Display...........................2-57
Automatic Dimming Rearview with OnStar
®,
Compass and Temperature Display.............2-55
Manual Rearview Mirror................................2-55
Outside Manual Mirrors................................2-58
Outside Power Foldaway Mirrors....................2-61
Outside Power Mirrors..................................2-59
Outside Trailer-Tow Mirrors...........................2-59
MP3 ..................................................3-102, 3-106
MyGMLink.com................................................ 7-4
N
Navigation System, Privacy..............................7-18
Navigation/Radio System, see Navigation
Manual.....................................................3-112
New Vehicle Break-In......................................2-22
Noise Control System, Tampering......................5-56
O
Odometer......................................................3-36
Odometer, Trip...............................................3-36
Off-Road Driving.............................................4-12Off-Road Recovery..........................................4-10
Oil
Engine.......................................................5-15
Pressure Gage............................................3-50
Pressure Light.............................................3-51
Oil, Engine Oil Life System..............................5-18
Older Children, Restraints................................1-35
Online Owner Center........................................ 7-4
OnStar, Privacy..............................................7-18
OnStar
®System, see OnStar®Manual...............2-65
Operation, Universal Home Remote System........2-69
Other Warning Devices...................................... 3-8
Outlet Adjustment............................................3-33
Outlets
Accessory Power.........................................3-23
Outside
Manual Mirrors............................................2-58
Power Foldaway Mirrors...............................2-61
Power Mirrors.............................................2-59
Trailer-Tow Mirrors.......................................2-59
Overheated Engine Protection
Operating Mode..........................................5-33
Owner Checks and Services.............................6-11
Owners, Canadian............................................... ii
9

Tilt Wheel........................................................ 3-9
Time, Setting..................................................3-81
Tire
Pressure Light.............................................3-47
Tires.............................................................5-66
Aluminum or Chrome-Plated Wheels,
Cleaning...............................................5-118
Buying New Tires........................................5-84
Chains.......................................................5-90
Changing a Flat Tire....................................5-92
Cleaning...................................................5-119
Different Size..............................................5-86
Dual Tire Operation.....................................5-76
If a Tire Goes Flat.......................................5-91
Ination - Tire Pressure................................5-74
Inspection and Rotation................................5-81
Installing the Spare Tire................................5-98
Pressure Monitor Operation...........................5-78
Pressure Monitor System..............................5-76
Removing the Flat Tire.................................5-98
Removing the Spare Tire and Tools...............5-93
Secondary Latch System............................5-105
Spare Tire................................................5-112
Storing a Flat or Spare Tire and Tools..........5-108
Tire Sidewall Labeling..................................5-67
Tire Terminology and Denitions....................5-71
Uniform Tire Quality Grading.........................5-86
Wheel Alignment and Tire Balance.................5-88Tires (cont.)
Wheel Replacement.....................................5-88
When It Is Time for New Tires......................5-84
Tow/Haul Mode...............................................2-34
Tow/Haul Mode Light.......................................3-53
Towing
Recreational Vehicle.....................................4-50
Towing a Trailer..........................................4-55
Your Vehicle...............................................
4-50
Traction
StabiliTrak
®System....................................... 4-6
Trailer
Recommendations.......................................4-94
Transmission
Fluid, Automatic..................................5-22, 5-25
Transmission Operation, Automatic....................2-28
Trip Odometer................................................3-36
Truck-Camper Loading Information....................4-47
Turn and Lane-Change Signals.........................3-10
Turn Signal/Multifunction Lever........................... 3-9
U
Ultrasonic Rear Parking Assist (URPA)...............2-63
Uniform Tire Quality Grading............................5-86
Universal Home Remote System.......................2-68
Operation...................................................2-69
Using this Manual............................................... iii
13