2003 GMC YUKON DENALI sensor

When Should an Air Bag Inflate?
Frontal Air Bags
The driver’s and right front passenger’s frontal air bags
are designed
to inflate in moderate to severe frontal
or near-frontal crashes. But they are designed to inflate
only
if the impact speed is above the system’s
designed “threshold level.”
In addition, your vehicle has “dual stage” frontal air
bags, which adjust the amount of restraint according to
crash severity. For moderate frontal impacts, these
air bags inflate at a level less than full deployment. For
more severe frontal impacts, full deployment occurs.
If the front of your vehicle goes straight into a wall that
doesn’t move or deform, the threshold level for the
reduced deployment is about
10 to 16 mph
(16 to 25 km/h), and the threshold level for a full
deployment is about
20 to 25 mph (32 to 40 km/h).
The threshold level can vary, however, with specific
vehicle design,
so that it can be somewhat above
or below this range.
If your vehicle strikes something that will move or
deform, such as a parked car, the threshold level will be
higher. The driver’s and right front passenger’s frontal
air bags are not designed
to inflate in rollovers, rear
impacts, or in many side impacts because inflation
would not help the occupant.
Seat Position Sensors
Vehicles with dual stage air bags are also equipped with
special sensors which enable the sensing system to
monitor
the position of both the driver and passenger
front seats. The seat position sensor provides information which is used
to determine if the air bags
should deploy at a reduced level or at full depoyment.
Side Impact Air Bags
Your vehicle may or may not have a side impact air
bag. See
Air Bag Systems on page 1-72. Side impact air
bags are designed
to inflate in moderate to severe
side crashes.
A side impact air bag will inflate if
the crash severity is above the system’s designed
“threshold level.” The threshold level can vary with
specific vehicle design. Side impact air bags are
not designed
to inflate in frontal or near-frontal impacts,
rollovers or rear impacts, because inflation would not
help the occupant.
A side impact air bag will only deploy
on the side of the vehicle that is struck.
Air Bag Systems
In any particular crash, no one can say whether an air
bag should have inflated simply because of the damage
to a vehicle or because of what the repair costs were.
For frontal air bags, inflation is determined by the angle
of the impact and how quickly the vehicle slows down
1-77

In many crashes severe enough to inflate an air bag,
windshields are broken by vehicle deformation.
Additional windshield breakage may also occur from the
right front passenger air bag.
Air bags are designed to inflate only once. After an
air bag inflates, you’ll need some new parts for
your air bag system. If you don’t get them, the air
bag system won’t be there to help protect you
in another crash.
A new system will include air bag
modules and possibly other parts. The service
manual for your vehicle covers the need to replace
other parts.
Your vehicle is equipped with electronic frontal
sensors which help the sensing system distinguish
between a moderate and a more severe frontal
impact. Your vehicle is also equipped with a crash
sensing and diagnostic module, which records
information about the frontal air bag system. The
module records information about the readiness of
the system and when the system commands
are bag inflation. It records the status
of the driver’s safety belt usage in
a crash in which the air bag
deploys or a crash in which the air bag nearly
deploys. The module also records speed, engine
RPM, brake and throttle data.
Let only qualified technicians work on your air bag
systems. Improper service can mean that an air
bag system won’t work properly. See your dealer for
service.
Notice: If you damage the covering for the driver’s
or the right front passenger’s air bag, or the air
bag covering
on the driver’s and right front
passenger’s seatback, the bag may not work
properly. You may have to replace the air bag
module in the steering wheel, both the air bag
module and the instrument panel for the right front
passenger’s air bag, or both the air bag module
and seatback for the driver’s and right front passenger’s side impact air bag.
Do not open or
break the air bag coverings.
1-80

Passenger Sensing System
If your rearview mirror has one of the indicators pictured
in the following illustrations, your vehicle has a passenger
sensing system. The indicator will be visible when you
turn your ignition key
to START or RUN. The words ON
and OFF or the symbol for on and off, will be visible on
the rearview mirror during the system check. When the
system check
is complete, either the word ON or the word
OFF, or the symbol for on or the symbol for off will be
visible. See Passenger
Air Bag Status Indicator on
page 3-32. If your rearview mirror doesn’t have either of
the indicators pictured, then your vehicle doesn’t have the
passenger sensing system.
L
Passenger Air Bag Status Indicator - United States Passenger
Air Bag
Status Indicator
- Canada
The passenger sensing system will turn off the right
front passenger’s frontal air bag under certain
conditions. The driver’s air bag and the side air bags
are not part
of the passenger sensing system.
The passenger sensing system works with sensors that
are part of the right front passenger’s seat and safety
belt. The sensors are designed to detect the presence of
a properly-seated occupant and determine
if the
passenger’s frontal air bag should be enabled
(may inflate) or not.
Accident statistics show that children are safer
if they
are restrained in the rear rather than the front seat.
General Motors, therefore, recommends that child
restraints be secured in a rear seat including an infant
riding in a rear-facing infant seat, a child riding in a
forward-facing child seat and an older child riding in a
booster seat. Never put a child in rear facing child
1-81

Automatic Headlamp System
When it is dark enough outside and the headlamp
switch is in AUTO, your automatic headlamp system will
turn on your headlamps at the normal brightness
along with other lamps such as the taillamps,
sidemarker, parking lamps, roof marker lamps and the
instrument panel lights. The radio lights will also be dim.
To turn off the automatic headlamp system, turn the
exterior lamps switch
to the off position and then
release.
Your vehicle has a light sensor located on the top of the
instrument panel. Be sure
it is not covered, or the
system will be on whenever the ignition is on.
The system may also turn on your headlamps when
driving through a parking garage, heavy overcast
weather or a tunnel. This is normal.
There is a delay in the transition between the daytime
and nighttime operation of the Daytime Running
Lamps (DRL) and the automatic headlamp systems
so
that driving under bridges or bright overhead street
lights does not affect the system. The DRL and
automatic headlamp system will only be affected when
the light sensor sees a change in lighting lasting
longer than the delay. If
you start your vehicle in a dark garage, the automatic
headlamp system will come on immediately. Once
you leave the garage,
it will take approximately
one minute for the automatic headlamp system to
change
to DRL if it is light outside. During that delay,
your instrument panel cluster may not be as bright
as usual. Make sure your instrument panel brightness
control is in the full bright position. See ”Instrument
Panel Brightness” under lnterior
Lamps on page 3-76.
Lamps On Reminder
If a door is open, a reminder chime will sound when
your headlamps or parking lamps are manually turned
on and your key is out of the ignition. To turn off
the chime, turn the headlamp switch
to off or AUTO and
then back on. In the automatic mode, the headlamps
turn off once the ignition is in LOCK and the headlamps
on at exit delay ends
(if enabled in the DIC).
Daytime Running Lamps
Daytime Running Lamps (DRL) can make it easier for
others
to see the front of your vehicle during the
day. DRL can be helpful in many different driving
conditions, but they can be especially helpful in the short
periods after dawn and before sunset. Fully functional
daytime running lamps are required on all vehicles
first sold in Canada.
3-1 4

The DRL system will come on when the following
conditions are met:
0 The ignition is on,
the exterior lamps control is in AUTO,
the transmission is not in PARK (P), and
0 the light sensor determines it is daytime.
When the DRL are on, only your DRL lamps will be on
The taillamps, sidemarker and other lamps won’t be
on. The instrument panel won’t be
lit up either.
When it begins
to get dark, the automatic headlamp
system will switch from DRL
to the headlamps.
As with any vehicle, you should turn on the regular
headlamp system when you need it.
Puddle Lamps
Your vehicle is equipped with puddle lamps to help you
see the area near the base of the front doors when
it
is dark out. The puddle lamps will illuminate when a door
is opened or when you press the unlock button on the
keyless entry transmitter. The lamps will time out or turn
off once the engine is started.
Fog Lamps
Use the fog lamps for better vision in foggy or misty
conditions. Your parking lamps and/or low-beam
headlamps must be on for your fog lamps
to work.
The fog lamp button
is
located on the left side of
your instrument panel.
Press the button
to turn the fog lamps on while the
headlamps or parking lamps are on. Press the button
again to turn them
off. An indicator light will glow
near the button when the fog lamps are on.
Remember, fog lamps alone will not give
off as much
light as your headlamps. Never use your fog lamps
in the dark without turning on the headlamps.
The fog lamps will go
off whenever your high-beam
headlamps come on. When the high beams go
off, the
fog lamps will come on again.
3-1 5

2. Set the driver’s and passenger’s temperature.
To find your comfort setting, start with a
74°F (23°C)
temperature setting and allow about
20 minutes
for the system to regulate. Turn the driver’s or
passenger’s side temperature knob
to adjust the
temperature setting as necessary.
If you choose the temperature setting of 60°F
(15°C) the system will remain at the maximum
cooling setting.
If you choose the temperature
setting of
90°F (32°C) the system will remain at the
maximum heat setting. Choosing either maximum
setting will not cause the vehicle to heat or cool
any faster.
Be careful not to cover the sensor located on the
top of the instrument panel near the windshield. This
sensor regulates air temperature based on sun
load, and also turns on your headlamps.
To avoid blowing cold air in cold weather, the
system will delay turning on the fan until warm air is
available. The length of delay depends on the
engine coolant temperature. Pressing the fan switch
will override this delay and change the fan to a
selected speed.
Manual Operation
You may manually adjust the air delivery mode or
fan speed.
0 (Off): Press this button to turn off the entire climate
control system. Outside air will still enter the vehicle, and
will be directed
to the floor. This direction can be changed
by pressing the mode button. The temperature can also
be adjusted using either temperature knob. Press the up
or down arrows on the fan switch, the defrost button, the
AUTO button, or the air conditioning button to turn the
system on when it is
off.
v (Fan): The switch with the fan symbol allows
you
to manually adjust the fan speed. Press the up
arrow
to increase fan speed and the down arrow
to decrease fan speed.
Pressing this button when the system
is off will turn the
system on.
% *d (Mode): Press this button to manually change the
direction of the airflow in your vehicle; keep pressing the
button until the desired mode appears on the display.
If you press the mode button to select an air delivery
mode, the display will change to show you the selected
air mode delivery. The display will then show the
current status of the system. When the system is turned
off, the display will go blank after displaying the
current status of the system.
3-21

Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows the air bag symbol. The system
checks the air bag’s electrical system for malfunctions.
The light tells you
if there is an electrical problem.
The system check includes the air bag sensors, the air
bag modules, the wiring and the crash sensing and
diagnostic module. For more information on the air bag
system, see
Air Bag Systems on page 1-72.
This light will come on
when you start your
vehicle, and it will flash for
a few seconds. Then
the light should go out.
This means the system
is ready.
If the air bag readiness light stays on after you start the
vehicle or comes on when you are driving, your air
bag system may not work properly. Have your vehicle
serviced right away.
16 the air bag readiness light stays on after yscl
start your vehicle,
it means the air bag system
may not be working properly. The air bags
in
your vehicle may not inflate in a crash, or they could even inflate without a crash.
To help
avoid injury to yourself or others, have your
vehicle serviced right away
if the air bag
readiness light stays on after you start your
vehicle.
The air bag readiness light should flash for a few
seconds when you turn the ignition key to RUN. If the
light doesn’t come on then, have it fixed
so it will
be ready to warn you
if there is a problem.
3-31

*I - Gasoline Engine and Fuel Injection Rail #2.
*2 - Gasoline Engine and Fuel Injection Rail #l.
*3 - Gasoline Engine; Oxygen Sensors.
*4 - Gasoline Engine; Oxygen Sensors.
*5 - PCM Ignition
I Fuses I Usage I
I STUD #1 I
Battery-and Diesels
Only)/Dual Battery (TP2) Do
not -install fuse.
Mid Bussed Electrical Center
MBEC Power
Feed, Front Seats,
LBEC Door Modules, Door Locks,
Auxiliary Power Outlet-Rear
Cargo Area and Instrument
Panel
STUD 2 Accessory
Powerflrailer
Wirinq Brake Feed LBEC
1
~~
I RR PARK I
Right
Rear Parking and
Sidemarker LamDs
I
5-93