ECU GMC ENVOY 2008 Service Manual

XM Radio Messages
If you have a Radio with CD or Radio with Six-Disc CD,
you can receive these radio display messages.
XL (Explicit Language Channels):These channels,
or any others, can be blocked at a customer’s request,
by calling 1-800-852-XMXM (9696).
Updating:The encryption code in the receiver is being
updated, and no action is required. This process should
take no longer than 30 seconds.
No Signal:The system is functioning correctly, but the
vehicle is in a location that is blocking the XM™ signal.
When the vehicle is moved into an open area, the signal
should return.
Loading XM:The audio system is acquiring and
processing audio and text data. No action is needed.
This message should disappear shortly.
CH Off Air:This channel is not currently in service.
Tune to another channel.
CH Unavail:This previously assigned channel is no
longer assigned. Tune to another station. If this station
was one of the presets, choose another station for
that preset button.
No Info:No artist, song title, category, or text
information is available at this time on this channel.
The system is working properly.Not Found:There are no channels available for the
selected category. The system is working properly.
XM Locked:The XM™ receiver in the vehicle may
have previously been in another vehicle. For security
purposes, XM™ receivers cannot be swapped between
vehicles. If this message is received after having your
vehicle serviced, check with your dealer/retailer.
Radio ID:If tuned to channel 0, this message alternates
with the XM™ Radio 8 digit radio ID label. This label
is needed to activate the service.
Unknown:If this message is received when tuned
to channel 0, there could be a receiver fault. Consult
with your dealer/retailer.
Chk XMRcvr:If this message does not clear within a
short period of time, the receiver could have a fault.
Consult with your dealer/retailer.
If you have a Radio with CD (MP3), you can receive
these radio display messages.
XL (Explicit Language Channels):These channels,
or any others, can be blocked at a customer’s request,
by calling 1-800-852-XMXM (9696).
Updating:The encryption code in the receiver is being
updated, and no action is required. This process
should take no longer than 30 seconds.
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No Signl:The system is functioning correctly, but the
vehicle is in a location that is blocking the XM™ signal.
When the vehicle is moved into an open area, the signal
should return.
Loading:The radio system is acquiring and processing
audio and text data. No action is needed. This message
should disappear shortly.
Off Air:This channel is not currently in service. Tune
to another channel.
CH Unavl:This previously assigned channel is no
longer assigned. Tune to another station. If this station
was one of the presets, choose another station for
that preset button.
No Info:No artist, song title, category, or text
information is available at this time on this channel.
The system is working properly.
NotFound:There are no channels available for the
selected category. The system is working properly.
XM Lock:The XM™ receiver in your vehicle may
have previously been in another vehicle. For security
purposes, XM™ receivers cannot be swapped between
vehicles. If this message is received after having your
vehicle serviced, check with your dealer/retailer.Radio ID:If tuned to channel 0, this message will
alternate with the XM™ Radio eight digit radio ID label.
This label is needed to activate the service.
Unknown:If this message is received when tuned to
channel 0, there could be a receiver fault. Consult
with your dealer/retailer.
Check XM:If this message does not clear within
a short period of time, the receiver could have a fault.
Consult with your dealer/retailer.
Navigation/Radio System
Your vehicle may have a navigation radio system.
The navigation system has built-in features intended to
minimize driver distraction. Technology alone, no matter
how advanced, can never replace your own judgment.
See the Navigation System manual for some tips to help
you reduce distractions while driving.
Rear Seat Entertainment (RSE)
System
Your vehicle may have the Digital Versatile Disc (DVD)
Rear Seat Entertainment (RSE) system. The RSE system
includes a DVD player, a video display screen, two sets
of wireless headphones, and a remote control.
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{(Subtitle):Press to turn on subtitles and to move
through subtitle options when a DVD is playing. The
format and content of this function will vary for each disc.
[(Fast Forward):Press to fast forward the DVD
or CD. To stop fast forwarding, press again. This button
might not work while the DVD is playing the copyright
information or the previews.
s(Play/Pause):Press to start play of a DVD or CD.
Press while a DVD or CD is playing to pause it. Press
again to continue the play of the DVD or CD.
When the DVD is playing, press this button then press
the fast forward button. The DVD continues playing
in a slow play mode. To cancel slow play mode, press
this button.
u(Next Track/Chapter):Press to advance to the
beginning of the next track or chapter. This button might
not work when the DVD is playing the copyright
information or the previews.
Battery Replacement
To change the remote control batteries, do the following:
1. Remove the battery compartment door located on
the bottom of the remote control.
2. Replace the two batteries in the compartment.
Make sure that they are installed correctly, using
the diagram on the inside of the battery
compartment.
3. Close the battery door securely.
If the remote control is to be stored for a long period of
time, remove the batteries and keep them in a cool,
dry place.
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“Off-roading” means you have left the great North
American road system behind. Traffic lanes are
not marked. Curves are not banked. There are no
road signs. Surfaces can be slippery, rough, uphill, or
downhill. In short, you have gone right back to nature.
Off-road driving involves some new skills. And that
is why it is very important that you read this guide.
You will nd many driving tips and suggestions. These
will help make your off-road driving safer and more
enjoyable.
Before You Go Off-Roading
There are some things to do before you go out.
For example, be sure to have all necessary maintenance
and service work done. Check to make sure all
underbody shields, if the vehicle has them, are
properly attached.
Be sure you read all the information about your
four-wheel-drive vehicle in this manual.
Is there enough fuel? Is the spare tire fully inated?
Are the uid levels up where they should be? What
are the local laws that apply to off-roading where you will
be driving? If you do not know, you should check with
law enforcement people in the area. Will you be on
someone’s private land? If so, be sure to get the
necessary permission.
Loading Your Vehicle for Off-Road
Driving
{CAUTION:
Cargo on the load oor piled higher than
the seatbacks can be thrown forward during
a sudden stop. You or your passengers
could be injured. Keep cargo below the
top of the seatbacks.
Unsecured cargo on the load oor can be
tossed about when driving over rough
terrain. You or your passengers can be
struck by ying objects. Secure the cargo
properly.
Heavy loads on the roof raise the vehicle’s
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the roof.
Keep cargo in the cargo area as far forward
and low as possible.
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There are some important things to remember about
how to load your vehicle.
The heaviest things should be on the load oor and
forward of the rear axle. Put heavier items as far
forward as you can.
Be sure the load is secured properly, so driving on
the off-road terrain does not toss things around.
You will nd other important information in this manual.
SeeLoading Your Vehicle on page 4-34,Luggage
Carrier on page 2-58, andTires on page 5-57.
Environmental Concerns
Off-road driving can provide wholesome and satisfying
recreation. However, it also raises environmental
concerns. We recognize these concerns and urge every
off-roader to follow these basic rules for protecting the
environment:
Always use established trails, roads, and areas that
have been specially set aside for public off-road
recreational driving; obey all posted regulations.
Avoid any driving practice that could damage the
environment — shrubs, owers, trees, grasses — or
disturb wildlife. This includes wheel-spinning,
breaking down trees, or unnecessary driving
through streams or over soft ground.
Always carry a litter bag — make sure all refuse is
removed from any campsite before leaving.
Take extreme care with open res where permitted,
camp stoves, and lanterns.
Never park your vehicle over dry grass or other
combustible materials that could catch re from
the heat of the vehicle’s exhaust system.
Traveling to Remote Areas
It makes sense to plan your trip, especially when
going to a remote area. Know the terrain and plan your
route. You are much less likely to get bad surprises.
Get accurate maps of trails and terrain. Try to learn of
any blocked or closed roads.
It is also a good idea to travel with at least one other
vehicle. If something happens to one of them, the other
can help quickly.
Does your vehicle have a winch? If so, be sure to read
the winch instructions. In a remote area, a winch can be
handy if you get stuck. But you will want to know how to
use it properly.
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Winter Driving
Here are some tips for winter driving:
Have your vehicle in good shape for winter.
You might want to put winter emergency supplies in
your vehicle.
Include an ice scraper, a small brush or broom, a supply
of windshield washer uid, a rag, some winter outer
clothing, a small shovel, a ashlight, a red cloth, and
reective warning triangles. And, if you will be driving
under severe conditions, include a small bag of sand,
a piece of old carpet, or a couple of burlap bags to help
provide traction. Be sure you properly secure these
items in your vehicle.
Also seeTires on page 5-57.
Driving on Snow or Ice
Most of the time, those places where the tires meet the
road probably have good traction.
However, if there is snow or ice between the tires
and the road, you can have a very slippery situation.
You have a lot less traction, or grip, and need to be
very careful.What is the worst time for this? Wet ice. Very cold snow
or ice can be slick and hard to drive on. But wet ice can
be even more trouble because it can offer the least
traction of all. You can get wet ice when it is about
freezing, 32°F (0°C), and freezing rain begins to fall.
Try to avoid driving on wet ice until salt and sand crews
can get there.
Whatever the condition — smooth ice, packed, blowing,
or loose snow — drive with caution.
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{CAUTION:
Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (GAWR). If you do,
parts on your vehicle can break, and it
can change the way your vehicle handles.
These could cause you to lose control
and crash. Also, overloading can shorten
the life of your vehicle.
Using heavier suspension components to get
added durability might not change your vehicle’s
weight ratings. Ask your dealer to help you
load your vehicle the right way.
Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
If you put things inside your vehicle — like
suitcases, tools, packages, or anything else — they
will go as fast as the vehicle goes. If you have to
stop or turn quickly, or if there is a crash, they will
keep going.
{CAUTION:
Things you put inside your vehicle can
strike and injure people in a sudden stop
or turn, or in a crash.
Put things in the cargo area of your
vehicle. Try to spread the weight
evenly.
Never stack heavier things, like
suitcases, inside the vehicle so that
some of them are above the tops of
the seats.
Do not leave an unsecured child
restraint in your vehicle.
When you carry something inside the
vehicle, secure it whenever you can.
Do not leave a seat folded down unless
you need to.
There is also important loading information for
off-road driving in this manual. See “Loading Your
Vehicle for Off-Road Driving” underOff-Road
Driving on page 4-13.
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4. Securely attach the vehicle being towed to the tow
vehicle.
{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in PARK (P).
You or others could be injured. Make sure the
parking brake is rmly set before you shift the
transfer case to NEUTRAL.
5. Shift the transfer case to NEUTRAL (N). See
Four-Wheel Drive on page 2-29for the proper
procedure to select the NEUTRAL (N) position
for your vehicle.
6. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle.
7. Turn the ignition off.
After towing, see “Shifting Out of Neutral” under
Four-Wheel Drive on page 2-29.
Dolly Towing
Front Towing (Front Wheels Off
the Ground)
Two-Wheel-Drive Vehicles
Notice:If you tow a two-wheel-drive vehicle with
the rear wheels on the ground, the transmission
could be damaged. The repairs would not be
covered by your warranty. Never tow your vehicle
with the rear wheels on the ground.
Four-Wheel-Drive Vehicles
Four-wheel-drive vehicles can be dolly towed with the
rear wheels on the ground.
Use the following procedure to tow your vehicle:
1. Drive the vehicle onto the tow dolly.
2. Shift the automatic transmission to PARK (P).
3. Turn the engine off, but leave the ignition on.
4. Firmly set the parking brake.
5. Securely attach the vehicle being towed to
the dolly.
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4. Follow the dolly manufacturer’s instructions to
attach and secure the vehicle being towed to
the dolly and then the loaded dolly to the tow
vehicle. Use an adequate clamping device to ensure
that the front wheels are locked into the straight
position.
5. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle.
6. Turn the ignition to LOCK.
If the tow vehicle will not be started or driven for
six weeks or more, remove the battery cable
from the negative terminal (post) of the battery.
Electronically Controlled Air
Suspension System
Your vehicle may be equipped with an electronically
controlled air suspension system that automatically
keeps your vehicle level as you load and unload.
The system includes a compressor, two height
sensors and two air springs supporting the rear axle.The system also has an internal clock to prevent
overheating if the inator is used for prolonged periods.
If the system overheats, all leveling function stops
until the system cools down. During this time, the
indicator light on the air inator switch will be ashing.
The ignition has to be on for the system to inate,
in order to raise the vehicle to the standard ride height
after loading. The system can lower the vehicle to
the standard ride height after unloading with the ignition
on and also for up to 30 minutes after the ignition
has been turned off.
You may hear the compressor operating when you load
your vehicle, and periodically as the system adjusts
the vehicle to the standard ride height.
Load leveling will not function normally with the inator
hose attached to the inator outlet. Remove the inator
hose from the outlet during loading and unloading.
If the vehicle is parked for an extended period of time,
some bleed down of the suspension is normal. Upon
starting the vehicle, proper height will be achieved.
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Driving with a Trailer
{CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon monoxide
(CO) could come into your vehicle. You can not
see or smell CO. It can cause unconsciousness
or death. SeeEngine Exhaust on page 2-37.
To maximize your safety when towing a trailer:
Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main heating
or cooling system on and with the fan on
any speed. This will bring fresh, outside air
into your vehicle. Do not use the climate
control setting for maximum air because it
only recirculates the air inside your vehicle.
SeeDual Climate Control System on
page 3-21.Towing a trailer requires a certain amount of
experience. Before setting out for the open road, you’ll
want to get to know your rig. Acquaint yourself with the
feel of handling and braking with the added weight of the
trailer. And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connection, lamps,
tires and mirror adjustment. If the trailer has electric
brakes, start your vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that
the load is secure, and that the lamps and any trailer
brakes are still working.
Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
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