2004 GMC YUKON ECU

Q:Because I have a disability, I have to get my
vehicle modied. How can I nd out whether
this will affect my advanced air bag system?
A:Changing or moving any parts of the front seats,
safety belts, the air bag sensing and diagnostic
module (located under the driver’s seat), or
the inside rearview mirror can affect the operation
of the advanced air bag system. If you have
questions, call Customer Assistance. The phone
numbers and addresses for Customer Assistance
are in Step Two of the Customer Satisfaction
Procedure in this manual. SeeCustomer
Satisfaction Procedure on page 7-2.
Restraint System Check
Checking Your Restraint Systems
Now and then, make sure the safety belt reminder light
and all your belts, buckles, latch plates, retractors
and anchorages are working properly. Look for any other
loose or damaged safety belt system parts. If you see
anything that might keep a safety belt system from doing
its job, have it repaired.
Torn or frayed safety belts may not protect you in a
crash. They can rip apart under impact forces. If a belt
is torn or frayed, get a new one right away.
Also look for any opened or broken air bag covers, and
have them repaired or replaced. (The air bag system
does not need regular maintenance.)
1-87

Keys...............................................................2-3
Remote Keyless Entry System.........................2-4
Remote Keyless Entry System Operation...........2-5
Doors and Locks.............................................2-8
Door Locks....................................................2-8
Power Door Locks..........................................2-9
Delayed Locking...........................................2-10
Programmable Automatic Door Locks..............2-10
Rear Door Security Locks..............................2-12
Lockout Protection........................................2-13
Liftgate........................................................2-13
Windows........................................................2-15
Manual Windows..........................................2-16
Power Windows............................................2-16
Sun Visors...................................................2-17
Theft-Deterrent Systems..................................2-18
Content Theft-Deterrent.................................2-18
Passlock
®....................................................2-20
Starting and Operating Your Vehicle................2-20
New Vehicle Break-In....................................2-20
Ignition Positions..........................................2-21
Starting Your Engine.....................................2-22
Adjustable Throttle and Brake Pedal................2-23
Engine Coolant Heater..................................2-23Automatic Transmission Operation...................2-24
Four-Wheel Drive..........................................2-28
All-Wheel Drive with Stabilitrak
®......................2-33
Parking Brake..............................................2-37
Shifting Into Park (P).....................................2-38
Shifting Out of Park (P).................................2-41
Parking Over Things That Burn.......................2-41
Engine Exhaust............................................2-42
Running Your Engine While You Are Parked.......2-42
Mirrors...........................................................2-43
Manual Rearview Mirror.................................2-43
Automatic Dimming Rearview Mirror with
OnStar
®, Compass and Temperature
Display....................................................2-44
Automatic Dimming Rearview Mirror with
Compass and Temperature Display..............2-46
Outside Manual Mirrors..................................2-49
Outside Camper-Type Mirrors.........................2-49
Outside Power Mirrors...................................2-50
Outside Power Camper-Type Mirror.................2-50
Outside Power Foldaway Mirrors.....................2-50
Outside Automatic Dimming Mirror..................2-51
Outside Curb View Assist Mirrors....................2-52
Outside Convex Mirror...................................2-52
Outside Heated Mirrors..................................2-52
Section 2 Features and Controls
2-1

1. Insert a dime, or similar object, in the slot between
the covers of the transmitter housing near the key
ring hole. Remove the bottom by twisting the dime.
2. Remove and replace the battery with a three-volt
CR2032 or equivalent battery, positive (+) side up.
3. Align the covers and snap them together.
4. Resynchronize the transmitter.
5. Check the operation of the transmitter.
Resynchronization
Resynchronization may be necessary due to the
security method used by this system. The transmitter
does not send the same signal twice to the receiver. The
receiver will not respond to a signal that has been
sent previously. This prevents anyone from recording
and playing back the signal from the transmitter.
To resynchronize your transmitter, stand close to your
vehicle and press and hold the LOCK and UNLOCK
buttons on the transmitter at the same time for 15
seconds. The door locks should cycle to conrm
synchronization. If the locks do not cycle, see your
dealer for service.
2-7

3. You are now ready to program the automatic door
locks. Select one of the four programming options
listed previously, and press the unlock side of
the power door lock switch to cycle through the
unlocking options. You will have 30 seconds
to begin programming. If you exceed the 30-second
limit, the locks will automatically lock and unlock
and the horn will chirp twice to indicate that
you have left the program mode. If this occurs,
repeat the procedure beginning with Step 1
to re-enter the programming mode.
You can exit the program mode any time by turning the
ignition to RUN. The locks will automatically lock and
unlock and the horn will chirp twice to indicate that you
are leaving the program mode. If the lock/unlock
switches are not pressed while in the programming
mode, the current auto lock/unlock setting will not be
modied.
See your dealer for more information.
Rear Door Security Locks
If your vehicle is equipped with this feature, you can
lock the rear side doors so they cannot be opened from
the inside by passengers.This feature is located on
the inside edge of the
rear doors.
To use one of the locks do the following:
1. Open one of the rear doors.
2. To engage the rear door security locks, move the
lever forward.
3. To disengage the lock, move the lever rearward.
4. Close the door.
5. Do the same thing to the other rear door.
The rear doors of your vehicle cannot be opened from
the inside when this feature is in use. If you want to
open the rear door while the security lock is engaged,
unlock the door and open the door from the outside.
2-12

Liftgate Glass and Liftgate
To open a mechanical lock system from the outside,
insert the key into the lock and turn it counterclockwise
to unlock the glass and liftgate.
The liftgate glass can be opened using the button on
the liftgate after the doors have been unlocked. This can
be done by using either the power door locks or the
remote keyless entry system.
To open the entire liftgate, lift the handle located in the
center of the door.
To lock a power lock system from the outside, insert the
key into the lock button and turn clockwise. All doors will
lock. You may also use the keyless entry system or the
power door locks to lock the liftgate and liftgate glass.
Panel Doors
To open the rear panel doors, you must open the
passenger’s side panel door rst. If the door is locked,
insert your door key in the lock and turn it
counterclockwise to unlock it.
To open the passenger’s side panel door, pull on the
handle and pull the door open.
To open the driver’s side panel door, rst open the
passenger’s side door. Then, pull the handle on the left
door edge out and pull the door open.
To close the doors, close the driver’s side door rst.
After securely closing the door, close the passenger’s
side door. Make sure both doors are latched securely.
To lock the rear doors from outside the vehicle, put your
key in the lock and turn it clockwise. If you have
power door locks, you can lock the side doors as well
as the rear doors from inside the vehicle. For more
information, seePower Door Locks on page 2-9earlier
in this section.
2-14

Theft-Deterrent Systems
Vehicle theft is big business, especially in some cities.
Although your vehicle has a number of theft-deterrent
features, we know that nothing we put on it can make it
impossible to steal. However, there are ways you
can help.
Content Theft-Deterrent
Your vehicle may be equipped with a content
theft-deterrent alarm system.
With this system, the
security light will ash as
you open the door, with the
ignition off, to let you
know that you are
activating the system.
This message reminds you to activate the theft-deterrent
system. Here’s how to do it:
1. Open the door.2. Lock the door with the power door lock switch or
the remote keyless entry transmitter. The security
light should come on and ash. If using the
remote keyless entry transmitter, the door does not
need to be open.
If the delayed locking feature is active, the alarm
will not be activated until all doors are closed
and the security light goes off.
3. Close all doors. The security light will stop ashing
and stay solid. The light should go off after
approximately 30 seconds. The alarm is not armed
until the security light goes off.
If a door is opened without the key or the remote
keyless entry transmitter, the alarm will go off. Your
vehicle’s headlamps will ash and the horn will sound for
about two minutes, then will turn off to save the
battery power.
Remember, the theft-deterrent system won’t activate if
you lock the doors with a key or use the manual
door lock. It activates only if you use a power door lock
switch with the door open, or with the remote keyless
entry transmitter. You should also remember that
you can start your vehicle with the correct ignition key if
the alarm has been set off.
2-18

Here’s how to avoid setting off the alarm by accident:
If you don’t want to activate the theft-deterrent
system, the vehicle should be locked with the door
keyafterthe doors are closed.
Always unlock a door with a key, or use the remote
keyless entry transmitter. Unlocking a door any
other way will set off the alarm if the system
has been armed.
If you set off the alarm by accident, unlock any door with
the key. You can also turn off the alarm by pressing
UNLOCK on the remote keyless entry transmitter or by
placing the key in the ignition and turning it to START.
Testing the Alarm
The alarm can be tested by following these steps:
1. From inside the vehicle, lower the driver’s window
and open the driver’s door.
2. Activate the system by locking the doors with the
power door lock switch while the door is open, or
with the remote keyless entry transmitter.
3. Get out of the vehicle, close the door and wait for
the security light to go out.
4. Then reach in through the window, unlock the door
with the manual door lock and open the door. This
should set off the alarm.
If the alarm does not sound when it should but the
vehicle’s headlamps ash, check to see if the horn
works. The horn fuse may be blown. To replace
the fuse, seeFuses and Circuit Breakers on page 5-113.
If the alarm does not sound or the vehicle’s headlamps
do not ash, the vehicle should be serviced by an
authorized service center.
2-19

Passlock®
Your vehicle is equipped with the
Passlock®theft-deterrent system.
Passlock
®is a passive theft-deterrent system.
Passlock®enables fuel if the ignition lock cylinder is
turned with a valid key. If a correct key is not used or the
ignition lock cylinder is tampered with, fuel is disabled.
If the engine stalls and the security light ashes,
wait until the light stops ashing before trying to restart
the engine. Remember to release the key from
START as soon as the engine starts.
If the engine is running and the security light comes on,
you will be able to restart the engine if you turn the
engine off. However, your Passlock
®system is
not working properly and must be serviced by your
dealer. Your vehicle is not protected by Passlock
®at this
time. You may also want to check the fuse. See
Fuses and Circuit Breakers on page 5-113. See your
dealer for service.
In an emergency, call the GM Roadside Assistance
Center. SeeRoadside Assistance Program on page 7-6.
Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle does not need an elaborate
“break-in.” But it will perform better in the long run
if you follow these guidelines:
Keep your speed at 55 mph (88 km/h) or less for
the rst 500 miles (805 km).
Do not drive at any one speed — fast or
slow — for the rst 500 miles (805 km). Do not
make full-throttle starts.
Avoid making hard stops for the rst 200 miles
(322 km) or so. During this time your new brake
linings are not yet broken in. Hard stops with new
linings can mean premature wear and earlier
replacement. Follow this breaking-in guideline
every time you get new brake linings.
Do not tow a trailer during break-in. SeeTowing a
Trailer on page 4-63for more information.
2-20