2004 GMC SONOMA ECU

You can adjust the crossrails to handle loads of various
sizes. Just loosen the slider knobs at each end of
the crossrail and move them to where you want them.
Make sure both sides of the crossrails are even,
then tighten the slider knobs.
Be sure the cargo is properly loaded. Follow these
guidelines:
•Carrying small, heavy loads on the roof is not
recommended.
•Secure the load using the tie downs at both ends of
the crossrails. When loading cargo directly on the
roof panel, use the crossrails to keep the load from
shifting.
•If you need to carry long items, move the crossrails
as far apart as possible. Tie the load to the tie
downs provided. Also tie the load to the bumpers.
Do not tie the load so tightly that the crossrails
or side rails are damaged.
Notice:Loading cargo on the luggage carrier that
weighs more than 100 lbs. (45 kg) or hangs over the
rear or sides of the vehicle may damage your
vehicle. Load cargo so that it rests on the slats as
far forward as possible and against the side
rails, making sure to fasten it securely.Don’t exceed the maximum vehicle capacity when
loading your vehicle. For more information on vehicle
capacity and loading seeLoading Your Vehicle on
page 4-45.
To prevent damage or loss of cargo as you’re driving,
check now and then to make sure the luggage
carrier and cargo are still securely fastened.
Bed Rails
{CAUTION:
If your vehicle has bed rails, they are there for
appearance only. If you try to tie down a load
with them, or to secure things in your truck,
not only can it damage the bed rails, but the
load can loosen. This could cause injury to
you or others. Secure loads by using the cargo
tie-down loops, inside the truck bed area.
2-41

Instrument Panel Overview...............................3-2
Hazard Warning Flashers................................3-4
Other Warning Devices...................................3-5
Horn.............................................................3-5
Tilt Wheel.....................................................3-5
Turn Signal/Multifunction Lever.........................3-6
Exterior Lamps.............................................3-11
Interior Lamps..............................................3-15
Accessory Power Outlets...............................3-16
Ashtrays and Cigarette Lighter........................3-17
Climate Controls............................................3-18
Climate Control System.................................3-18
Outlet Adjustment.........................................3-20
Warning Lights, Gages and Indicators.............3-21
Instrument Panel Cluster................................3-22
Speedometer and Odometer...........................3-24
Trip Odometer..............................................3-24
Tachometer.................................................3-24
Safety Belt Reminder Light.............................3-24
Air Bag Readiness Light................................3-25
Charging System Light..................................3-26
Voltmeter Gage............................................3-26
Brake System Warning Light..........................3-27
Anti-Lock Brake System Warning Light.............3-28
Engine Coolant Temperature Gage..................3-28Malfunction Indicator Lamp.............................3-29
Oil Pressure Gage........................................3-32
Security Light...............................................3-33
Service Four-Wheel Drive Warning Light..........3-33
Check Gages Warning Light...........................3-34
Fuel Gage...................................................3-34
Low Fuel Warning Light.................................3-35
Audio System(s).............................................3-35
Setting the Time for Radios without Radio
Data Systems (RDS)..................................3-35
Setting the Time for Radios with Radio
Data Systems (RDS)..................................3-36
AM-FM Radio...............................................3-36
Radio with CD..............................................3-39
Radio with Cassette and CD..........................3-49
Radio with Six-Disc CD.................................3-59
Theft-Deterrent Feature (Non-RDS Radios).......3-73
Theft-Deterrent Feature (RDS Radios).............3-73
Understanding Radio Reception......................3-74
Care of Your Cassette Tape Player.................3-74
Care of Your CDs.........................................3-75
Care of Your CD Player................................3-76
Fixed Mast Antenna......................................3-76
XM™ Satellite Radio Antenna System
(48 Contiguous US States).........................3-76
Section 3 Instrument Panel
3-1

Security Light
This light will come on
briefly when you turn the
key toward START.
The light will stay on until
the engine starts.
If the light flashes, the Passlock
®system has entered a
tamper mode. If the vehicle fails to start, seePasslock®
on page 2-16.
If the light comes on continuously while driving and
stays on, there may be a problem with the Passlock
®
system. Your vehicle will not be protected by Passlock®,
and you should see your dealer.
Also, seeContent Theft-Deterrent on page 2-14for
additional information regarding the SECURITY light.
Service Four-Wheel Drive
Warning Light
If you have this light, it
should come on briefly
when you turn on the
ignition, as a check
to show you it is working.
The SERVICE 4WD light comes on to indicate that
there may be a problem with the four-wheel drive system
and service is required. Malfunctions can be indicated
by the system before any problem is apparent,
which may prevent serious damage to the vehicle. This
system is also designed to assist your service
technician in correctly diagnosing a malfunction.
3-33

XM™ Radio Messages (cont’d)
Radio Display
MessageCondition Action Required
No Info Song/Program Title not
availableNo song title information is available at this time on this
channel. Your system is working properly.
No Info Category Name not
availableNo category information is available at this time on this
channel. Your system is working properly.
No Info No Text/Informational
message availableNo text or informational messages are available at this time
on this channel. Your system is working properly.
Not Found No channel available for
the chosen categoryThere are no channels available for the category you
selected. Your system is working properly.
XM Lock Theft lock active The XM receiver in your vehicle may have previously been
in another vehicle. For security purposes, XM receivers
cannot be swapped between vehicles. If you receive this
message after having your vehicle serviced, check with the
servicing facility.
Radio ID Radio ID label
(channel 0)If you tune to channel 0, you will see this message
alternating with your XM Radio 8 digit radio ID label. This
label is needed to activate your service.
Unknown Radio ID not known
(should only be if
hardware failure)If you receive this message when you tune to channel 0,
you may have a receiver fault. Consult with your dealer.
Check XM Hardware failure If this message does not clear within a short period of time,
your receiver may have a fault. Consult with your retail
location.
3-46

XM™ Radio Messages (cont’d)
Radio Display
MessageCondition Action Required
No Info Category Name not
availableNo category information is available at this time on this
channel. Your system is working properly.
No Info No Text/Informational
message availableNo text or informational messages are available at this time
on this channel. Your system is working properly.
Not Found No channel available for
the chosen categoryThere are no channels available for the category you
selected. Your system is working properly.
XM Locked Theft lock active The XM receiver in your vehicle may have previously been
in another vehicle. For security purposes, XM receivers
cannot be swapped between vehicles. If you receive this
message after having your vehicle serviced, check with the
servicing facility.
Radio ID Radio ID label
(channel 0)If you tune to channel 0, you will see this message
alternating with your XM Radio 8 digit radio ID label. This
label is needed to activate your service.
Unknown Radio ID not known
(should only be if
hardware failure)If you receive this message when you tune to channel 0, you
may have a receiver fault. Consult with your dealer.
Chk XMRcvr Hardware failure If this message does not clear within a short period of time,
your receiver may have a fault. Consult with your retail
location.
3-67

Off-Road Driving with Your
Four-Wheel-Drive Vehicle
This off-road guide is for vehicles that have four-wheel
drive.
Also, seeAnti-Lock BrakesunderBraking on page 4-6.
Off-road driving can be great fun. But it does have
some definite hazards. The greatest of these is
the terrain itself.
“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 find 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 so equipped) 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 inflated? Are the fluid
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
There are some important things to remember about
how to load your vehicle.
•The heaviest things should be on the load floor and
forward of your 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.
4-14

{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.
You will find other important information in this manual.
SeeLoading Your Vehicle on page 4-45,Luggage
Carrier on page 2-40andTires on page 5-57.
Environmental Concerns
Off-road driving can provide wholesome and satisfying
recreation. However, it also raises environmental
concerns. GM 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, flowers, 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 fires (where
permitted), camp stoves and lanterns.
•Never park your vehicle over dry grass or other
combustible materials that could catch fire from
the heat of the vehicle’s exhaust system.
4-15

Winter DrivingHere are some tips for winter driving:
•Have your vehicle in good shape for winter.
•You may want to put winter emergency supplies in
your vehicle.
Include an ice scraper, a small brush or broom, a
supply of windshield washer fluid, a rag, some winter
outer clothing, a small shovel, a flashlight, a red
cloth and a couple of reflective 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.
4-38