sensor CHEVROLET TRAIL BLAZER 2008 1.G Owners Manual

When Should an Airbag Inate?
Frontal airbags are designed to inate in moderate to
severe frontal or near-frontal crashes to help reduce the
potential for severe injuries mainly to the driver’s or
right front passenger’s head and chest. However, they
are only designed to inate if the impact exceeds a
predetermined deployment threshold. Deployment
thresholds are used to predict how severe a crash is
likely to be in time for the airbags to inate and
help restrain the occupants.
Whether your frontal airbags will or should deploy is not
based on how fast your vehicle is traveling. It depends
largely on what you hit, the direction of the impact,
and how quickly your vehicle slows down.
Frontal airbags may inate at different crash speeds.
For example:
If the vehicle hits a stationary object, the airbags
could inate at a different crash speed than if the
vehicle hits a moving object.
If the vehicle hits an object that deforms, the
airbags could inate at a different crash speed than
if the vehicle hits an object that does not deform.
If the vehicle hits a narrow object (like a pole),
the airbags could inate at a different crash
speed than if the vehicle hits a wide object
(like a wall).
If the vehicle goes into an object at an angle, the
airbags could inate at a different crash speed
than if the vehicle goes straight into the object.
Thresholds can also vary with specic vehicle design.
Frontal airbags are not intended to inate during vehicle
rollovers, rear impacts, or in many side impacts.
In addition, your vehicle has dual-stage frontal airbags.
Dual-stage airbags adjust the restraint according to
crash severity. Your vehicle has electronic frontal
sensors, which help the sensing system distinguish
between a moderate frontal impact and a more severe
frontal impact. For moderate frontal impacts, dual-stage
airbags inate at a level less than full deployment.
For more severe frontal impacts, full deployment occurs.
Your vehicle has seat position sensors which enables
the sensing system to monitor the position of the driver’s
and right front passenger’s seat. The sensors provide
information that is used to determine if the airbags
should deploy at a reduced level or at full deployment.
1-56

Passenger Sensing System
Your vehicle has a passenger sensing system for the
right front passenger’s position. The passenger
airbag status indicator will be visible in the rearview
mirror when you start your vehicle.The words ON and OFF, or the symbol for on and off,
will be visible 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. SeePassenger Airbag Status Indicator on
page 3-35.
The passenger sensing system will turn off the right
front passenger’s frontal airbag under certain conditions.
The driver’s airbags 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. The sensors
are designed to detect the presence of a properly-seated
occupant and determine if the right front passenger’s
frontal airbag should be enabled (may inate) or not.
Accident statistics show that children are safer if they
are restrained in the rear rather than the front seat.
We recommend that children be secured in a rear seat,
including: an infant or a child riding in a rear-facing
child restraint; a child riding in a forward-facing child
seat; an older child riding in a booster seat; and children,
who are large enough, using safety belts. United States
Canada
1-60

Adding Equipment to Your
Airbag-Equipped Vehicle
Q:Is there anything I might add to or change
about the vehicle that could keep the airbags
from working properly?
A:Yes. If you add things that change your vehicle’s
frame, bumper system, height, front end or side
sheet metal, they may keep the airbag system from
working properly. Changing or moving any parts of
the front seats, safety belts, the airbag sensing and
diagnostic module, steering wheel, instrument panel,
roof-rail airbag modules, ceiling headliner or pillar
garnish trim, rearview mirror, front sensors, rollover
sensor module, or airbag wiring can affect the
operation of the airbag system.
In addition, your vehicle has a passenger sensing
system for the right front passenger’s position, which
includes sensors that are part of the passenger’s
seat. The passenger sensing system may not
operate properly if the original seat trim is replaced
with non-GM covers, upholstery or trim, or with GM
covers, upholstery or trim designed for a different
vehicle. Any object, such as an aftermarket seat
heater or a comfort enhancing pad or device,
installed under or on top of the seat fabric, could also
interfere with the operation of the passenger sensingsystem. This could either prevent proper deployment
of the passenger airbag(s) or prevent the passenger
sensing system from properly turning off the
passenger airbag(s). SeePassenger Sensing
System on page 1-60.
If you have any questions about this, you should
contact Customer Assistance before you modify
your vehicle. 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.
If your vehicle has rollover roof-rail airbags, see
Different Size Tires and Wheels on page 5-77
for additional important information.
Q:Because I have a disability, I have to get my
vehicle modied. How can I nd out whether
this will affect my airbag system?
A: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. See
Customer Satisfaction Procedure on page 7-2.
In addition, your dealer/retailer and the service manual
have information about the location of the airbag
sensors, sensing and diagnostic module and airbag
wiring.
1-65

Daytime Running Lamps (DRL)
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 DRL are
required on all vehicles rst sold in Canada.
The DRL system makes the headlamps come on at
reduced brightness when the following conditions
are met:
The ignition is on.
The exterior lamps knob is in automatic
headlamp mode.
The light sensor detects daytime light.
The transmission is not in PARK (P).
When the DRL are on, only the headlamps will be on.
The taillamps, sidemarker and other lamps will not
be on. The instrument panel will not be lit up either.
When it begins to get dark, the headlamps automatically
switch from DRL to the regular headlamps.
Automatic Headlamp System
When it is dark enough outside, the Automatic
Headlamp System turns on the headlamps when the
vehicle is started and after the transaxle has been
shifted out of the PARK (P) position. The headlamps,
taillamps, sidemarker, and parking lamps will come
on. The instrument panel lights and radio lights will also
turn on at normal brightness. Once on, the system
remains on during these conditions even if the vehicle
is shifted back into PARK (P).
The vehicle has a light sensor on the top of the
instrument panel. Make sure it is not covered or the
system may come on whenever the ignition is on and
the vehicle is shifted out of the PARK (P) position.
The system could also turn on the lamps when driving
through a parking garage, heavy overcast weather
or a tunnel. This is normal.
3-15

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 are only 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 comes on after the transmission is
shifted out of PARK (P). Once you leave the garage, it
will take about one minute for the automatic headlamp
system to change to DRL if it is light outside. During that
delay, the instrument panel cluster might not be as
bright as usual. Make sure the instrument panel
brightness control is in the full bright position.
If the vehicle is running and the automatic headlamp
system is already on, it can be turned off by turning and
releasing the headlamp control at the off position.
The automatic headlamp system stays off until you turn
and release the headlamp control at the off position
again. SeeHeadlamps on page 3-14.Fog Lamps
Your vehicle may have this feature. Use your fog lamps
for better vision in foggy or misty conditions. Your
ignition must be in RUN for your fog lamps to work.
The fog lamp button is
located on the instrument
panel to the right of
the exterior lamps knob.
Press the button to turn the fog lamps on. Press the
button again to turn them off. A light will glow near the
button while the fog lamps are on. Fog lamps will
turn off whenever your high-beam headlamps are on.
Some localities have laws that require the headlamps to
be on along with the fog lamps.
3-16

Airbag Readiness Light
There is an airbag readiness light on the instrument
panel cluster, which shows the airbag symbol.
The system checks the airbag’s electrical system for
malfunctions. The light tells you if there is an electrical
problem. The system check includes the airbag
sensor, the pretensioners, the airbag modules, the
wiring and the crash sensing and diagnostic module.
For more information on the airbag system, seeAirbag
System on page 1-51.
This light will come on
when you start your
vehicle, and it will ash for
a few seconds. The light
should go out and the
system is ready.
If the airbag readiness light stays on after you start
the vehicle or comes on when you are driving,
your airbag system may not work properly.
Have your vehicle serviced right away.{CAUTION:
If the airbag readiness light stays on after you
start your vehicle, it means the airbag system
may not be working properly. The airbags in
your vehicle may not inate in a crash, or they
could even inate without a crash. To help
avoid injury to yourself or others, have your
vehicle serviced right away.
The airbag readiness light should ash for a few seconds
when you start the engine. If the light does not come on
then, have it xed immediately. If there is a problem with
the airbag system, an airbag Driver Information Center
(DIC) message may also come on. SeeDIC Warnings
and Messages on page 3-53for more information.
3-34

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.
Overload Protection
The air suspension system is equipped with overload
protection. Overload protection is designed to protect the
air suspension system, and it is an indicator to the
driver that the vehicle is overloaded. When the overload
protection mode is on, it will not allow damage to the
air compressor. However, do not overload the vehicle.
SeeLoading Your Vehicle on page 4-35.
If the suspension remains at a low height, the rear axle
load has exceeded GAWR (Gross Axle Weight Rating).
When the overload protection mode is activated, the
compressor operates for about 30 seconds to one minute
without raising the vehicle depending on the amount
of overload. This will continue each time the ignition
is turned on until the rear axle load is reduced
below GAWR.
4-47

If your vehicle has P255/50R20 104V size tires installed
on the rear axle, they will require ination pressure
adjustment when driving your vehicle at speeds above 99
mph (160 km/h). Set the cold ination pressure, for the
rear tires only, to the maximum ination pressure shown
on the tire sidewall, or 38 psi (262 kPa), whichever is
lower. See the example following. When you end this
high-speed driving, return the tires to the cold tire ination
pressure shown on the Tire and Loading Information
label. SeeLoading Your Vehicle on page 4-35.
Example:
You will nd the maximum load and ination pressure
molded on the tire’s sidewall, in small letters, near
the rim ange. It will read something like this: Maximum
load 690 kg (1521 lbs) 300 kPa (44 psi) Max. Press.
For this example, you would set the ination pressure for
high-speed driving at 38 psi (262 kPa).
The ination pressure for the front tires should be set to
the cold tire ination pressure shown on the Tire and
Loading Information label.
Racing or other competitive driving may affect the
warranty coverage of your vehicle. See your warranty
booklet for more information.Tire Pressure Monitor System
The Tire Pressure Monitor System (TPMS) uses radio
and sensor technology to check tire pressure levels. The
TPMS sensors monitor the air pressure in your vehicle’s
tires and transmit tire pressure readings to a receiver
located in the vehicle.
Each tire, including the spare (if provided), should be
checked monthly when cold and inated to the ination
pressure recommended by the vehicle manufacturer on
the vehicle placard or tire ination pressure label. (If your
vehicle has tires of a different size than the size indicated
on the vehicle placard or tire ination pressure label, you
should determine the proper tire ination pressure for
those tires.)
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system (TPMS)
that illuminates a low tire pressure telltale when one or
more of your tires is signicantly under-inated.
Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires as soon
as possible, and inate them to the proper pressure.
Driving on a signicantly under-inated tire causes the
tire to overheat and can lead to tire failure. Under-ination
also reduces fuel efficiency and tire tread life, and may
affect the vehicle’s handling and stopping ability.
5-67

Tire Pressure Monitor Operation
The Tire Pressure Monitor System (TPMS) is designed to
warn the driver when a low tire pressure condition exists.
TPMS sensors are mounted onto each tire and wheel
assembly, excluding the spare tire and wheel assembly.
The TPMS sensors monitor the air pressure in the
vehicle’s tires and transmit the tire pressure readings to a
receiver located in the vehicle.
The TPMS is designed to alert the driver if a low tire
pressure condition exists. If your vehicle has the Driver
Information Center (DIC) steering wheel control buttons,
tire pressure levels may also be checked through the
DIC. See “Tire Pressures” underDIC Operation and
Displays on page 3-50.
When a low tire pressure
condition is detected, the
TPMS illuminates the
low tire pressure warning
light located on the
instrument panel cluster.At the same time a message to check the pressure in a
specic tire appears on the Driver Information Center
(DIC) display. The low tire pressure warning light and the
DIC warning message come on at each ignition cycle
until the tires are inated to the correct ination pressure.
Using the DIC, tire pressure levels can be viewed by the
driver. For additional information and details about the
DIC operation and displays seeDIC Operation and
Displays on page 3-50andDIC Warnings and Messages
on page 3-53.
The low tire pressure warning light may come on in cool
weather when the vehicle is rst started, and then turn off
as you start to drive. This could be an early indicator that
the air pressure in the tire(s) is low and needs to be
inated to the proper pressure.
A Tire and Loading Information label, attached to your
vehicle, shows the size of your vehicle’s original
equipment tires and the correct ination pressure for your
vehicle’s tires when they are cold. SeeLoading Your
Vehicle on page 4-35, for an example of the Tire and
Loading Information label and its location on your vehicle.
Also seeInflation - Tire Pressure on page 5-65.
5-69

Your vehicle’s TPMS can alert you about a low tire
pressure condition but it does not replace normal tire
maintenance. SeeTire Inspection and Rotation on
page 5-72andTires on page 5-58.
Notice:Liquid tire sealants could damage the Tire
Pressure Monitor System (TPMS) sensors. Sensor
damage caused by using a tire sealant is not covered
by your warranty. Do not use liquid tire sealants.
TPMS Malfunction Light and Message
The TPMS will not function properly if one or more of the
TPMS sensors are missing or inoperable. When the
system detects a malfunction, the low tire warning light
ashes for about one minute and then stays on for the
remainder of the ignition cycle. A DIC warning message
is also displayed. The low tire warning light and DIC
warning message come on at each ignition cycle until the
problem is corrected. Some of the conditions that can
cause the malfunction light and DIC message to come
on are:
One of the road tires has been replaced with the
spare tire. The spare tire does not have a TPMS
sensor. The TPMS malfunction light and DIC
message should go off once you re-install the road
tire containing the TPMS sensor.
The TPMS sensor matching process was started but
not completed or not completed successfully after
rotating the vehicle’s tires. The DIC message and
TPMS malfunction light should go off once the TPMS
sensor matching process is performed successfully.
See “TPMS Sensor Matching Process” later in this
section.
One or more TPMS sensors are missing or
damaged. The DIC message and the TPMS
malfunction light should go off when the TPMS
sensors are installed and the sensor matching
process is performed successfully. See your dealer/
retailer for service.
Replacement tires or wheels do not match your
vehicle’s original equipment tires or wheels. Tires
and wheels other than those recommended for your
vehicle could prevent the TPMS from functioning
properly. SeeBuying New Tires on page 5-75.
Operating electronic devices or being near facilities
using radio wave frequencies similar to the TPMS
could cause the TPMS sensors to malfunction.
If the TPMS is not functioning it cannot detect or signal a
low tire condition. See your dealer/retailer for service if
the TPMS malfunction light and DIC message come on
and stay on.
5-70