ECU GMC ENVOY 2008 Workshop Manual

Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixture at the coolant recovery tank.
{CAUTION:
Turning the radiator pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. With the coolant recovery tank, you will
almost never have to add coolant at the
radiator. Never turn the radiator pressure
cap — even a little — when the engine and
radiator are hot.
Add coolant mixture at the recovery tank, but be careful
not to spill it.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.Occasionally check the coolant level in the radiator.
For information on how to add coolant to the radiator,
seeCooling System on page 5-30.
Radiator Pressure Cap
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
SeeEngine Compartment Overview on page 5-12for
information on location.
Engine Overheating
You will nd a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-40for more information.
If your vehicle has a Driver Information Center (DIC),
the display will show an Engine Coolant Hot/Engine
Overheated message. SeeDIC Warnings and Messages
on page 3-53for more information.
5-28

Headlamps
To replace one of these bulbs:
1. Open the hood.Hood Release on page 5-11for
more information.
2. Lift the two headlamp retaining clips.
3. Pull the headlamp assembly away from the vehicle
to access the electrical connectors.4. Remove the cover from the headlamp bulb.
5. Remove the bulb socket that needs to be replaced
by turning it counterclockwise.
6. Disconnect the electrical connector from the
old bulb.
7. Plug the electrical connector into the new bulb
using care not to touch the glass with your
ngers.
8. Install the new bulb into the socket and turn it
clockwise to secure.
9. Reinstall by reversing Steps 1 through 6.
10. Press down on the headlamp retaining clips to
secure the headlamp assembly.
5-50

Front Turn Signal, Sidemarker and
Parking Lamps
To replace one of these bulbs:
1. Follow Steps 1 through 3 underHeadlamps on
page 5-50to access the front turn signal,
sidemarker or parking lamp.
2. Turn the bulb socket counterclockwise and remove
it from the lamp assembly.
3. Holding the socket, pull the old bulb to release it
from the socket.
4. Push the new bulb into the socket until it clicks.
5. Insert the bulb socket into the lamp assembly and
turn it clockwise to secure.
6. Reinstall the headlamp assembly by lining up the
headlamp assembly with the slots in the headlamp
retaining clips.
7. Press down on the headlamp retaining clips to
secure the headlamp assembly.
Taillamps, Turn Signal, and
Stoplamps
To replace a stoplamp/taillamp or turn signal bulb:
1. Open the liftgate. SeeLiftgate/Liftglass on
page 2-12for more information.
2. Remove the
two screws from the
taillamp assembly.
3. Pull the assembly away from the vehicle.
5-51

Back-Up Lamps
The back-up lamps are
located in the rear bumper.
To replace a bulb:
1. Reach behind the rear bumper and locate the bulb
socket.
2. Turn it counterclockwise to remove from the lamp
assembly.
3. Holding the socket, pull the old bulb to release it
from the socket.
4. Push in a new bulb into the bulb socket until it
clicks.
5. Reinstall the bulb socket into the lamp assembly
and turn it clockwise to secure.
License Plate Lamp
1. Remove the two screws holding the license plate
lamp lens.
2. Pull the lens away from the lamp assembly.
3. Pull the old bulb straight out from the bulb socket.
4. Install the new bulb.
5. Replace the lamp assembly lens and tighten the
screws.
5-53

Reset the Tire Pressure Monitor System. SeeTire
Pressure Monitor Operation on page 5-69.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specifications on page 5-120.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after time. The wheel could
come off and cause an accident. When
you change a wheel, remove any rust or
dirt from places where the wheel attaches
to the vehicle. In an emergency, you can
use a cloth or a paper towel to do this;
but be sure to use a scraper or wire brush
later, if needed, to get all the rust or dirt
off. SeeChanging a Flat Tire on page 5-82.
Make sure the spare tire is stored securely. Push,
pull, and then try to rotate or turn the tire. If it
moves, tighten the cable. SeeStoring a Flat or
Spare Tire and Tools on page 5-96.
When It Is Time for New Tires
Various factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road conditions,
inuence when you need new tires.
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which appear
when your tires have only
1/16 inch (1.6 mm) or less
of tread remaining. Some
commercial truck tires may
not have treadwear
indicators.
5-73

Follow this diagram to store the underbody-mounted at
or spare tire.
A. Wheel Wrench
B. Hoist Shaft
C. Extension
D. Retainer
E. Spare or Flat Tire
(Valve Stem
Pointed Up)
1. Put the tire (E) on the ground at the rear of the
vehicle.
2. Remove the hubcap, if the vehicle has one, from
the at tire by tapping the backside of the hubcap
with the wheel wrench (A). Store in a safe location
until the at tire is repaired. Once the tire is
repaired, replace the hubcap.3. Make sure the valve stem is pointed up and to
the rear.
4. Pull the retainer (D) through the wheel.
5. Put the socket end of the extension (C) through the
hole just above the rear bumper at a 45 degree
angle downward. Connect the socket end of the
extension to the hoist shaft (B).
6. Raise the tire fully against the underside of the
vehicle. Continue turning the wheel wrench (A)
clockwise until you hear two clicks or feel it
skip twice. This indicates that the tire is secure and
the cable is tight. The spare tire hoist cannot be
overtightened.
5-97

7. Make sure the tire is stored securely. Push, pull (A),
and then try to turn (B) the tire. If the tire moves,
use the wheel wrench and socket end of the
extension to tighten the cable.
8. Return the equipment to the proper location in the
vehicle as shown next.A. Handle
B. Wheel Wrench
C. Instruction LabelD. Extension(s)
E. Knob
F. Wheel Blocks
and Jack
5-98

Owner Checks and Services
These owner checks and services should be performed
at the intervals specied to help ensure the safety,
dependability, and emission control performance of your
vehicle. Your dealer/retailer can assist you with these
checks and services.
Be sure any necessary repairs are completed at once.
Whenever any uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
inRecommended Fluids and Lubricants on page 6-12.
At Each Fuel Fill
It is important to perform these underhood checks at
each fuel fill.
Engine Oil Level Check
Notice:It is important to check the engine oil
regularly and keep it at the proper level. Failure to
keep the engine oil at the proper level can cause
damage to the engine not covered by your warranty.
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil on page 5-16.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOL®
coolant mixture if necessary. SeeEngine Coolant
on page 5-26.
Windshield Washer Fluid Level Check
Check the windshield washer uid level in the windshield
washer uid reservoir and add the proper uid if
necessary.
At Least Once a Month
Tire Ination Check
Inspect your vehicle’s tires and make sure they are
inated to the correct pressures. Do not forget to
check the spare tire. SeeInflation - Tire Pressure on
page 5-64. Check to make sure the spare tire is stored
securely. SeeChanging a Flat Tire on page 5-82.
Tire Wear Inspection
Tire rotation may be required for high mileage highway
drivers prior to the Engine Oil Life System service
notication. Check the tires for wear and, if necessary,
rotate the tires. SeeTire Inspection and Rotation on
page 5-72.
6-9

Roadside Assistance Program
For vehicles purchased in the U.S. call,
1-800-GMC-8782 (1-800-462-8782);
(Text telephone (TTY): 1-888-889-2438).
For vehicles purchased in Canada, call1-800-268-6800.
Service is available 24 hours a day, 365 days a year.
As the owner of a new GMC vehicle, you are
automatically enrolled in the GMC Roadside
Assistance program.
Who is Covered?
Roadside Assistance coverage is for the vehicle
operator, regardless of ownership. In Canada, a person
driving the vehicle without the consent of the owner
is not eligible for coverage.
Services Provided
The following services are provided in the U.S. and
Canada up to 5 years/100,000 miles (160 000 km),
whichever occurs rst, and, in Canada only, up
to a maximum coverage of $100.
Fuel Delivery:Delivery of enough fuel for the
vehicle to get to the nearest service station
(approximately $5 in Canada). In Canada, service
to provide diesel may be restricted. For safety
reasons, propane and other alternative fuels will
not be provided through this service.
Lock-out Service:Lock-out service will be
covered at no charge if you are unable to gain
entry into your vehicle. A remote unlock may
be available if you have an active OnStar
®
subscription. To ensure security, the driver must
present personal identication before lock-out
service is provided. In Canada, the vehicle
registration is also required.
Emergency Tow From a Public Roadway or
Highway:Tow to the nearest dealership for warranty
service or in the event of a vehicle-disabling crash.
Winch-out assistance is provided when the vehicle is
mired in sand, mud, or snow.
Flat Tire Change:Installation of a spare tire in good
condition, when equipped and properly inated, is
covered at no charge. The customer is responsible
for the repair or replacement of the tire if not covered
by a warrantable failure.
Jump Start:A battery jump start is covered at no
charge if the vehicle does not start.
7-8

Trip Routing Service:Upon request, Roadside
Assistance will send you detailed, computer
personalized maps, highlighting your choice of either
the most direct route or the most scenic route to your
destination, anywhere in North America, along with
helpful travel information pertaining to your trip.
Please allow three weeks before your planned
departure date. In Canada, trip routing requests will
be limited to six per calendar year.
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.
7-9