2008 CHEVROLET SILVERADO parking brake

When the System Does Not Seem to
Work Properly
If the URPA system will not activate due to a temporary
condition, the message PARKING ASSIST OFF will be
displayed on the DIC and a red light will be shown on the
rear URPA display when the shift lever is moved into
R (Reverse). This occurs under the following conditions:
The driver disables the system.
The parking brake pedal is depressed.
The ultrasonic sensors are not clean. Keep the
vehicle’s rear bumper free of mud, dirt, snow, ice and
slush. For cleaning instructions, seeWashing Your
Vehicle on page 5-118.
A trailer was attached to the vehicle, or a bicycle or
an object was hanging out of the tailgate during the
last drive cycle, the red light may illuminate in the
rear display. Once the attached object is removed,
URPA will return to normal operation.
A tow bar is attached to the vehicle.
The vehicle’s bumper is damaged. Take the vehicle
to your dealer/retailer to repair the system.
Other conditions may affect system performance,
such as vibrations from a jackhammer or the
compression of air brakes on a very large truck.
If the system is still disabled, after driving forward at
least 15 mph (25 km/h), take the vehicle to your
dealer/retailer.
OnStar®System
OnStar uses several innovative technologies and live
advisors to provide you with a wide range of safety,
security, information, and convenience services. If your
airbags deploy, the system is designed to make an
automatic call to OnStar Emergency advisors who can
request emergency services be sent to your location.
If you lock your keys in the vehicle, call OnStar at
1-888-4-ONSTAR and they can send a signal to unlock
your doors. If you need roadside assistance, press
the OnStar button and they can contact Roadside
Service for you.
OnStar service is provided to you subject to the
OnStar Terms and Conditions. You may cancel your
OnStar service at any time by contacting OnStar.
2-67

C. Driver Information Center (DIC) Buttons. SeeDriver
Information Center (DIC) on page 3-56.
D. Hazard Warning Flasher Button. SeeHazard
Warning Flashers on page 3-8.
E. Instrument Panel Cluster. SeeInstrument Panel
Cluster on page 3-37.
F. Shift Lever. SeeAutomatic Transmission Operation on
page 2-28. Tow/Haul Selector Button (If Equipped).
SeeTow/Haul Mode on page 2-34. Range Selection
Mode (Allison Transmission and Hydra-Matic
®
6-Speed Button (If Equipped). SeeAutomatic
Transmission Operation on page 2-28.
G. Audio System. SeeAudio System(s) on page 3-84.
H. Instrument Panel Storage Area. SeeInstrument
Panel Storage on page 2-78.
I. Integrated Trailer Brake Controller (If Equipped).
SeeTowing a Trailer on page 4-55.
J. Exterior Lamp Controls. SeeExterior Lamps on
page 3-17.
K. Hood Release. SeeHood Release on page 5-13.
L. Parking Brake. SeeParking Brake on page 2-50.
M. Dome Lamp Override Button. SeeDome Lamp
Override on page 3-21. Dome Lamp Knob.
SeeDome Lamps on page 3-21. Fog Lamp Button
(If Equipped). SeeFog Lamps on page 3-20.
N. Cruise Control Buttons. SeeCruise Control on
page 3-13.O. Tilt Wheel Lever. SeeTilt Wheel on page 3-8.
P. Horn. SeeHorn on page 3-8.
Q. Audio Steering Wheel Controls (If Equipped).
SeeAudio Steering Wheel Controls on page 3-132.
R. Automatic Transfer Case Control (If Equipped).
SeeFour-Wheel Drive on page 2-36.
S. Ashtray (If Equipped). SeeAshtray(s) and Cigarette
Lighter on page 3-24.
T. StabiliTrak
®Button (If Equipped). SeeStabiliTrak®
System on page 4-6. Ultrasonic Rear Park Assist
Disable Button (If Equipped). SeeUltrasonic
Rear Parking Assist (URPA) on page 2-64. Pedal
Adjust Button (If Equipped). SeeAdjustable Throttle
and Brake Pedal on page 2-26. Heated Windshield
Washer Fluid Button (If Equipped).Windshield
Washer on page 3-12.
U. Accessory Power Outlet. SeeAccessory Power
Outlet(s) on page 3-23.
V. Climate Control System. SeeClimate Control System
(With Air Conditioning ) on page 3-25orClimate
Control System (Heater Only) on page 3-28andDual
Automatic Climate Control System on page 3-29.
W. Power Take Off (PTO) Control (If Equipped).
See Power Take Off (PTO) in the Duramax Diesel
Supplement Index.
X. Passenger Airbag Off Control (If Equipped).
SeeAirbag Off Switch on page 1-78.
Y. Glove Box. SeeGlove Box on page 2-78.
3-5

E. Shift Lever. SeeAutomatic Transmission Operation
on page 2-28.
F. Tow/Haul Selector Button (If Equipped).
SeeTow/Haul Mode on page 2-34.
G. Driver Information Center (DIC) Controls. SeeDriver
Information Center (DIC) on page 3-56.
H. Audio System. SeeAudio System(s) on page 3-84.
I. Exterior Lamps Control. SeeExterior Lamps on
page 3-17.
J. Integrated Trailer Brake Controller (If Equipped).
SeeTowing a Trailer on page 4-55.
K. Dome Lamp Override Button. SeeDome Lamp
Override on page 3-21. Dome Lamp Knob.
SeeDome Lamps on page 3-21.
L. Automatic Transfer Case Control. (If Equipped).
SeeFour-Wheel Drive on page 2-36.
M. Hood Release. SeeHood Release on page 5-13.
N. Parking Brake. SeeParking Brake on page 2-50.
O. Cruise Control Buttons. SeeCruise Control on
page 3-13.
P. Tilt Wheel Lever. SeeTilt Wheel on page 3-8.
Q. Horn. SeeHorn on page 3-8.R. Audio Steering Wheel Controls. SeeAudio Steering
Wheel Controls on page 3-132.
S. Climate Controls. SeeClimate Control System
(With Air Conditioning ) on page 3-25orClimate
Control System (Heater Only) on page 3-28or
Dual Automatic Climate Controls (If Equipped).
SeeDual Automatic Climate Control System
on page 3-29.
T. Accessory Power Outlets. SeeAccessory Power
Outlet(s) on page 3-23. Cigarette Lighter
(If Equipped). SeeAshtray(s) and Cigarette Lighter
on page 3-24.
U. StabiliTrak
®Button (If Equipped). SeeStabiliTrak®
System on page 4-6. Pedal Adjust Button
(If Equipped). SeeAdjustable Throttle and Brake
Pedal on page 2-26. Rear Park Assist Disable Button
(If Equipped). SeeUltrasonic Rear Parking Assist
(URPA) on page 2-64. Heated Windshield Washer
Fluid Button (If Equipped). SeeWindshield Washer
on page 3-12.
V. Passenger Airbag Off Control (If Equipped).
SeeAirbag Off Switch on page 1-78.
W. Glove Box. SeeGlove Box on page 2-78.
3-7

Setting Cruise Control
Cruise control will not work if the parking brake is set, or
if the master cylinder brake uid level is low.
The cruise control light on the instrument panel cluster
will come on after the cruise control has been set to
the desired speed.
{CAUTION:
If you leave your cruise control on when you
are not using cruise, you might hit a button
and go into cruise when you do not want to.
You could be startled and even lose control.
Keep the cruise control switch off until you
want to use cruise control.
1. Press the cruise control On/Off button.
2. Get up to the desired speed.
3. Press the SET−button located on the steering
wheel and release it.
4. Take your foot off the accelerator.
Resuming a Set Speed
If the brakes are applied while the cruise control is set,
the cruise control is disengaged. But it does not
need to be reset.
Once the vehicle speed reaches about 25 mph
(40 km/h) or more, press the +RES button on the
steering wheel. The vehicle will go back to the
previous set speed and stay there.
Increasing Speed While Using Cruise
Control
To increase the cruise speed while using cruise control:
Press and hold the +RES button on the steering
wheel until the desired speed is reached, then
release it.
To increase vehicle speed in small increments,
press the +RES button. Each time this is done,
the vehicle goes about 1 mph (1.6 km/h) faster.
3-15

Readings outside the normal operating range may also
occur when a large number of electrical accessories
are operating in the vehicle and the engine is left idling
for an extended period. This condition is normal
since the charging system is not able to provide full
power at engine idle. As engine speeds are increased,
this condition should correct itself as higher engine
speeds allow the charging system to create maximum
power.
You can only drive for a short time with the readings
outside the normal operating range. If you must
drive, turn off all unnecessary accessories.
Readings outside the normal operating range indicate
a possible problem in the electrical system.
Have the vehicle serviced as soon as possible.Brake System Warning Light
With the ignition on, the brake system warning light will
come on when you set the parking brake. If you try to
drive with the parking brake engaged, a chime will sound
when the vehicle speed is greater than 5 mph (8 km/h).
Your vehicle’s hydraulic brake system is divided into two
parts. If one part is not working, the other part can
still work and stop you. For good braking, though, you
need both parts working well.
If the warning light comes on and a chime sounds there
could be a brake problem. Have your brake system
inspected right away.
This light may also come on due to low brake uid.
SeeBrakes on page 5-43for more information.
United States
Canada
3-46

SERVICE BRAKES SOON
This message displays if there is a problem with the
brake system. If this message appears, stop as soon as
possible and turn off the vehicle. Restart the vehicle
and check for the message on the DIC display.
If the message is still displayed or appears again when
you begin driving, the brake system needs service.
See your dealer/retailer.
SERVICE PARK ASSIST
If your vehicle has the Ultrasonic Rear Parking Assist
(URPA) system, this message displays if there is a
problem with the URPA system. Do not use this system
to help you park. SeeUltrasonic Rear Parking Assist
(URPA) on page 2-64for more information. See your
dealer/retailer for service.
SERVICE STABILITRAK
If your vehicle has StabiliTrak®and this message
displays, it means there may be a problem with the
StabiliTrak
®system. If you see this message, try to
reset the system. Stop; turn off the engine for at least
15 seconds; then start the engine again. If this message
still comes on, it means there is a problem. You should
see your dealer/retailer for service. The vehicle is safe
to drive, however, you do not have the benet of
StabiliTrak
®, so reduce your speed and drive accordingly.
SERVICE THEFT DETERRENT SYSTEM
This message displays when there is a problem with
the theft-deterrent system. The vehicle may or may not
restart so you may want to take the vehicle to your
dealer/retailer before turning off the engine. See
PASS-Key
®III+ Electronic Immobilizer Operation on
page 2-20for more information.
SERVICE TIRE MONITOR SYSTEM
If your vehicle has the Tire Pressure Monitor System
(TPMS), this message displays if a part on the system is
not working properly. The tire pressure light also ashes
and then remains on during the same ignition cycle.
SeeTire Pressure Light on page 3-49. Several conditions
may cause this message to appear. SeeTire Pressure
Monitor Operation on page 5-79for more information.
If the warning comes on and stays on, there may be a
problem with the TPMS. See your dealer/retailer.
SERVICE TRACTION CONTROL
If your vehicle has StabiliTrak®, this message displays
when there is a problem with the Traction Control
System (TCS). When this message displays, the system
will not limit wheel spin. Adjust your driving accordingly.
See your dealer/retailer for service. SeeStabiliTrak
®
System on page 4-6for more information.
3-72

There are some things you should do if the vehicle stalls,
or is about to stall, and you cannot make it up the hill:
Push the brake pedal to stop the vehicle and keep it
from rolling backwards. Also, apply the parking
brake.
If the engine is still running, shift the transmission to
REVERSE (R), release the parking brake, and slowly
back down the hill in REVERSE (R).
If the engine has stopped running, you will need to
restart it. With the brake pedal pressed and the
parking brake still applied, shift the transmission to
PARK (P) and restart the engine. Then, shift to
REVERSE (R), release the parking brake, and slowly
back down the hill as straight as possible in
REVERSE (R).
As you are backing down the hill, put your left hand
on the steering wheel at the 12 o’clock position. This
way, you will be able to tell if the wheels are straight
and maneuver as you back down. It is best that you
back down the hill with the wheels straight rather
than in the left or right direction. Turning the wheel
too far to the left or right will increase the possibility
of a rollover.There are also some things you must not do if you stall,
or are about to stall, when going up a hill:
Never attempt to prevent a stall by shifting into
NEUTRAL (N) to rev-up the engine and regain
forward momentum. This will not work. Your vehicle
will roll backwards very quickly and you could go
out of control.
Instead, apply the regular brake to stop the vehicle.
Then apply the parking brake. Shift to REVERSE (R),
release the parking brake, and slowly back
straight down.
Never attempt to turn around if you are about to
stall when going up a hill. If the hill is steep
enough to stall your vehicle, it is steep enough to
cause you to roll over if you turn around. If you
cannot make it up the hill, you must back straight
down the hill.
4-20

If, after stalling, you try to back down the hill and decide
you just cannot do it, set the parking brake, put the
transmission in PARK (P) and turn off the engine. Leave
the vehicle and go get some help. Exit on the uphill side
and stay clear of the path the vehicle would take if it rolled
downhill. Do not shift the transfer case to NEUTRAL
when you leave the vehicle. Leave it in some gear.
{CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P). This is because the
NEUTRAL position on the transfer case
overrides the transmission. You or someone
else could be injured. If you are going to leave
your vehicle, set the parking brake and shift the
transmission to PARK (P). But do not shift the
transfer case to NEUTRAL. Leave the transfer
case in the Two-Wheel High, Four-Wheel High
or Four-Wheel Low position.
Driving Downhill
When off-roading takes you downhill, you will want to
consider a number of things:
How steep is the downhill? Will I be able to maintain
vehicle control?
What is the surface like? Smooth? Rough?
Slippery? Hard-packed dirt? Gravel?
Are there hidden surface obstacles? Ruts? Logs?
Boulders?
What is at the bottom of the hill? Is there a hidden
creek bank or even a river bottom with large rocks?
4-21