
How the System Works
URPA comes on automatically when the shift lever is
moved into REVERSE (R) and the vehicle speed is less
than 3 mph (5 km/h). When the system turns on, the
three lights on the display will illuminate for one and a
half seconds to let you know that the system is
working. If your vehicle is moving in REVERSE (R) at a
speed greater than 3 mph (5 km/h), the red light will
ash to remind you that the system does not work at a
speed greater than 3 mph (5 km/h).
If an object is detected at a REVERSE (R) speed of
less than 3 mph (5 km/h), one of the following will occur:
Description English Metric
Amber light 5 ft 1.5 m
Amber/amber lights 40 in 1.0 m
Amber/amber/red lights &
continuous chime20 in 0.5 m
Amber/amber/red lights
ashing & continuous
chime1 ft 0.3 m
A chime will sound the rst time an object is detected
between 20 inches (0.5 m) and 5 feet (1.5 m) away.
URPA cannot detect objects that are above trunk level.
In order for the rear sensors to recognize an object,
it must be within detection range behind the vehicle.
When the System Does Not Seem to
Work Properly
The light may ash red when the vehicle is in
REVERSE (R), if the ultrasonic sensors are not kept
clean. So be sure to keep your rear bumper free of mud,
dirt, snow, ice and slush. Other conditions that may
affect system performance include things like the
vibrations from a jackhammer or the compression of air
brakes on a very large truck. If after cleaning the
rear bumper and then driving forward at least 15 mph
(25 km/h), the display continues to ash red, see
your dealer.
If a trailer was attached to your vehicle, or a bicycle or
an object was hanging out of your trunk during your
last drive cycle, the light may also ash red. The light will
continue to ash whenever in REVERSE (R) until
your vehicle is driven forward at least 15 mph (25 km/h)
without any obstructions behind the vehicle.
For cleaning instructions, seeWashing Your Vehicle on
page 5-98.
3-45

Brake System Warning Light
Your vehicle’s hydraulic brake system is divided into
two parts. If one part isn’t 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, there is a brake problem.
Have your brake system inspected right away.
This light should come on brie y when you turn the
engine on. If it does not come on then, have it xed so
it will be ready to warn you if there is a problem.When the ignition is on, the brake system warning light
will also come on when you set your parking brake. The
light will stay on if your parking brake does not release
fully. If it stays on after your parking brake is fully
released, it means you have a brake problem.
If the light comes on while you are driving, pull off the
road and stop carefully. You may notice that the pedal is
harder to push, or the pedal may go closer to the
oor. It may take longer to stop. If the light is still on,
have the vehicle towed for service. SeeTowing
Your Vehicle on page 4-37.
{CAUTION:
Your brake system may not be working properly
if the brake system warning light is on. Driving
with the brake system warning light on can lead
to an accident. If the light is still on after you
have pulled off the road and stopped carefully,
have the vehicle towed for service. United StatesCanada
3-64

Anti-Lock Brake System
Warning Light
With the anti-lock brake
system, the light will come
on when your engine is
started and may stay on
for several seconds.
That is normal.
If the ABS warning light comes on and stays on, there
may be a problem with the antilock portion of the
brake system. If the red BRAKE light is not on, you still
have brakes, but you do not have antilock brakes.
SeeBrake System Warning Light on page 3-64.
If the light stays on, press the ignition button to OFF/ACC.
If the light comes on when you are driving, stop as soon
as possible and turn the ignition off. Then start the engine
again to reset the system. If the light still stays on, or
comes on again while you are driving, your vehicle needs
service. If the regular brake system warning light is not
on, you still have brakes, but you do not have anti-lock
brakes. If the regular brake system warning light is also
on, you do not have anti-lock brakes and there is a
problem with your regular brakes. SeeBrake System
Warning Light on page 3-64.The anti-lock brake system warning light should come
on brie y when you turn the ignition on. If the light does
not come on then, have it xed so it will be ready to
warn you if there is a problem.
Low Tire Pressure Warning Light
This light will come on
brie y as you start the
engine, for vehicles
equipped with the Tire
Pressure Monitor System.
It will then come on only when a at or low tire pressure
condition exists.
SeeTire Pressure Monitor System on page 5-66for
more information.
3-65

If this message appears immediately after starting the
engine, it is possible that the generator can still recharge
the battery. The battery should recharge while driving
but may take a few hours to do so. Consider using
an auxiliary charger to boost the battery after returning
home or to a nal destination. Make sure you follow
the manufacturer’s instructions.
If this message appears while driving or after starting
your vehicle and stays on, have it checked immediately
to determine the cause of this problem.
To help the generator recharge the battery quickly, you
can reduce the load on the electrical system by
turning off the accessories.
The normal battery voltage range is 11.5 to 15.5 volts.
You can monitor battery voltage on the DIC by pressing
the information button until you nd BATTERY VOLTS.
CHANGE ENGINE OIL SOON
When this message displays, it means that service is
required for your vehicle. See your GM dealer. See
Engine Oil on page 5-18andScheduled Maintenance
on page 6-4for more information.
When you reset the CHANGE ENGINE OIL SOON
message by clearing it from the display, you still must
reset the engine oil life system separately. For more
information on resetting the engine oil life system, see
Engine Oil Life System on page 5-22.
CHECK BRAKE FLUID
This message will display if the ignition is on to inform
the driver that the brake uid level is low. Have the
brake system serviced by your GM dealer as soon as
possible. SeeBrake System Warning Light on page 3-64
for more information.
CHECK COOLANT LEVEL
This message will display when there is a low level of
engine coolant. Have the cooling system serviced
by your GM dealer as soon as possible. SeeEngine
Coolant on page 5-26for more information.
CHECK GAS CAP
When this message displays, the gas cap has not been
fully tightened. You should recheck the gas cap to
ensure that it is on and tightened properly.
CHECK OIL LEVEL
This message will display when the oil level is low. See
Engine Oil on page 5-18for more information on
checking your engine oil.
3-81

RADAR CRUISE NOT READY
When this message displays, it means that the Adaptive
Cruise Control system will not activate due to a
temporary condition. Your vehicle does not require
service. This message will also display when either of
the following conditions occurs:
The driver turns off the head-up display (HUD)
while the Adaptive Cruise Control is engaged.
The driver attempts to engage the Adaptive Cruise
Control while the HUD is off.
If this message appears when you attempt to activate
the system, continue driving for several minutes
and then try activating the system again.
RIGHT REAR DOOR AJAR
This symbol appears with
the RIGHT REAR DOOR
AJAR message.
When this message displays, it means that the
passenger’s side rear door was not closed completely.
You should check to make sure that the door is
closed completely.
SERVICE AC (Air Conditioning)
SYSTEM
This message will display when the electronic sensors
that control the air conditioning and heating systems are
no longer working. Have the climate control system
serviced by your GM dealer if you notice a drop
in heating and air conditioning efficiency.
SERVICE AIR BAG
This message will display when there is a problem with
the airbag system. Have your vehicle serviced by
your GM dealer immediately. SeeAirbag Readiness
Light on page 3-60for more information.
SERVICE BRAKE ASSIST
This message will display when a problem with the
panic brake assist system has been detected. Have your
vehicle serviced by your GM dealer.
SERVICE RADAR CRUISE
When this message displays, it means that the Adaptive
Cruise Control system is disabled and needs service.
See your GM dealer.
3-88

Control of a Vehicle
You have three systems that make your vehicle go where
you want it to go. They are the brakes, the steering, and
the accelerator. All three systems have to do their work at
the places where the tires meet the road.
Sometimes, as when you are driving on snow or ice,
it is easy to ask more of those control systems than the
tires and road can provide. That means you can lose
control of your vehicle. SeeTraction Control System
(TCS) on page 4-9andStabiliTrak
®System on
page 4-11.
Adding non-GM accessories can affect your vehicle’s
performance. SeeAccessories and Modi cations
on page 5-3.
Braking
SeeBrake System Warning Light on page 3-64.
Braking action involves perception time and
reaction time.
First, you have to decide to push on the brake pedal.
That is perception time. Then you have to bring up your
foot and do it. That is reaction time.
Average reaction time is about three-fourths of a
second. But that is only an average. It might be less
with one driver and as long as two or three seconds or
more with another. Age, physical condition, alertness,
coordination, and eyesight all play a part. So do alcohol,
drugs, and frustration. But even in three-fourths of a
second, a vehicle moving at 60 mph (100 km/h) travels
66 feet (20 m). That could be a lot of distance in an
emergency, so keeping enough space between
your vehicle and others is important.
And, of course, actual stopping distances vary greatly
with the surface of the road, whether it is pavement
or gravel; the condition of the road, whether it is
wet, dry, or icy; tire tread; the condition of your brakes;
the weight of the vehicle; and the amount of brake
force applied.
4-6

Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic. This is
a mistake. Your brakes may not have time to cool
between hard stops. Your brakes will wear out much
faster if you do a lot of heavy braking. If you keep pace
with the traffic and allow realistic following distances,
you will eliminate a lot of unnecessary braking.
That means better braking and longer brake life.
If your engine ever stops while you are driving, brake
normally but do not pump your brakes. If you do,
the pedal may get harder to push down. If your engine
stops, you will still have some power brake assist.
But you will use it when you brake. Once the power
assist is used up, it may take longer to stop and
the brake pedal will be harder to push.
Adding non-GM accessories can affect your vehicle’s
performance. SeeAccessories and Modi cations
on page 5-3.Anti-Lock Brake System (ABS)
Your vehicle has the Anti-Lock Brake System (ABS),
an advanced electronic braking system that will
help prevent a braking skid.
When you start your engine and begin to drive away,
ABS will check itself. You may hear a momentary motor
or clicking noise while this test is going on, and you
may even notice that your brake pedal moves a
little. This is normal.
If there is a problem with
ABS, this warning light will
stay on. SeeAnti-Lock
Brake System Warning
Light on page 3-65.
4-7