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118 Instruments and Controls
Voltmeter Gauge
Uplevel Shown, Base Level and MidlevelSimilar
When the ignition is on, this gauge indicates
the battery voltage.
When the engine is running, this gauge
shows the condition of the charging system.
The gauge can transition from a higher to
lower or a lower to higher reading. This is
normal. If the vehicle is operating outside
the normal operating range, the charging
system light comes on. See Charging System
Light 0120. The voltmeter gauge may also
read lower when in fuel economy mode.
This is normal. Readings outside the normal operating
range can 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.
The vehicle can only be driven for a short
time with the readings outside the normal
operating range. If the vehicle must be
driven, turn off all accessories, such as the
radio and air conditioner.
Readings outside the normal operating
range indicate a possible problem in the
electrical system. Have the vehicle serviced
as soon as possible.
Seat Belt Reminders
Driver Seat Belt Reminder Light
There is a driver seat belt reminder light on
the instrument cluster.
When the vehicle is started, this light
flashes and a chime may come on to remind
the driver to fasten their seat belt.
Then the light stays on solid until the belt is
buckled. This cycle may continue several
times if the driver remains or becomes
unbuckled while the vehicle is moving.
If the driver seat belt is buckled, neither the
light nor the chime comes on.
Front Passenger Seat Belt Reminder
Light
The vehicle may have a front passenger seat
belt reminder light near the passenger
airbag status indicator. See
Passenger
Sensing System 070.
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120 Instruments and Controls
will light either ON or OFF, or either the on
or off symbol, to let you know the status of
the front outboard passenger frontal airbag.
If the word ON or the on symbol is lit on
the passenger airbag status indicator, it
means that the front outboard passenger
frontal airbag is allowed to inflate.
If the word OFF or the off symbol is lit on
the passenger airbag status indicator, it
means that the passenger sensing system
has turned off the front outboard passenger
frontal airbag.
If, after several seconds, both status
indicator lights remain on, or if there are no
lights at all, there may be a problem with
the lights or the passenger sensing system.
See your dealer for service.
{Warning
If the airbag readiness light ever comes
on and stays on, it means that
something may be wrong with the airbag
system. To help avoid injury to yourself
or others, have the vehicle serviced right
away. SeeAirbag Readiness Light 0119
for more information, including important
safety information.
Charging System Light
The charging system light comes on briefly
when the ignition is turned on, but the
engine is not running, as a check to show
the light is working. It should go out when
the engine is started.
If the light stays on, or comes on while
driving, there may be a problem with the
electrical charging system. Have it checked
by your dealer. Driving while this light is on
could drain the battery.
When this light comes on, or is flashing, the
Driver Information Center (DIC) also displays
a message.
If a short distance must be driven with the
light on, be sure to turn off all accessories,
such as the radio and air conditioner. Find a
safe place to stop the vehicle.
Malfunction Indicator Lamp
(Check Engine Light)
This light is part of the vehicle’s emission
control on-board diagnostic system. If this
light is on while the engine is running, a
malfunction has been detected and the
vehicle may require service. The light should
come on to show that it is working when
the ignition is on and the engine is not
running. See Ignition Positions (Key Access)
0 221 or
Ignition Positions (Keyless Access) 0223.
Malfunctions are often indicated by the
system before any problem is noticeable.
Being aware of the light and seeking service
promptly when it comes on may prevent
damage.
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Instruments and Controls 121
Caution
If the vehicle is driven continually with
this light on, the emission control system
may not work as well, the fuel economy
may be lower, and the vehicle may not
run smoothly. This could lead to costly
repairs that might not be covered by the
vehicle warranty.
Caution
Modifications to the engine, transmission,
exhaust, intake, or fuel system, or the
use of replacement tires that do not
meet the original tire specifications, can
cause this light to come on. This could
lead to costly repairs not covered by the
vehicle warranty. This could also affect
the vehicle’s ability to pass an Emissions
Inspection/Maintenance test. See
Accessories and Modifications0302.
If the light is flashing : A malfunction has
been detected that could damage the
emission control system and increase vehicle
emissions. Diagnosis and service may be
required. To help prevent damage, reduce vehicle
speed and avoid hard accelerations and
uphill grades. If towing a trailer, reduce the
amount of cargo being hauled as soon as
possible.
If the light continues to flash, find a safe
place to park. Turn the vehicle off and wait
at least 10 seconds before restarting the
engine. If the light is still flashing, follow
the previous guidelines and see your dealer
for service as soon as possible.
If the light is on steady :
A malfunction has
been detected. Diagnosis and service may be
required.
Check the following:
.If fuel has been added to the vehicle
using the capless funnel adapter, make
sure that it has been removed. See
“Filling the Tank with a Portable Gas Can”
under Filling the Tank (Chassis Cab and
Box Delete Models) 0266 or
Filling the Tank (Pickup Models) 0265.
The diagnostic system can detect if the
adapter has been left installed in the
vehicle, allowing fuel to evaporate into
the atmosphere. A few driving trips with
the adapter removed may turn off the
light.
.Poor fuel quality can cause inefficient
engine operation and poor driveability,
which may go away once the engine is
warmed up. If this occurs, change the fuel
brand. It may require at least one full
tank of the proper fuel to turn the light
off. See Recommended Fuel 0263.
If the light remains on, see your dealer.
Emissions Inspection and Maintenance
Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the test
equipment will likely connect to the
vehicle's Data Link Connector (DLC).
The DLC is under the instrument panel to
the left of the steering wheel. Connecting
devices that are not used to perform an
Emissions Inspection/Maintenance test or to
service the vehicle may affect vehicle
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122 Instruments and Controls
operation. SeeAdd-On Electrical Equipment
0 297. See your dealer if assistance is
needed.
The vehicle may not pass inspection if:
.The light is on when the engine is
running.
.The light does not come on when the
ignition is on while the engine is off.
.Critical emission control systems have not
been completely diagnosed. If this
happens, the vehicle would not be ready
for inspection and might require
several days of routine driving before the
system is ready for inspection. This can
happen if the 12-volt battery has recently
been replaced or run down, or if the
vehicle has been recently serviced.
See your dealer if the vehicle will not pass
or cannot be made ready for the test.
Brake System Warning Light
MetricEnglish This light comes on briefly when the vehicle
is turned on to show that the light is
working. If it does not come on then, have
it fixed so it will be ready to warn you if
there is a problem.
If the light comes on and stays on, there is
a brake problem. Have the brake system
inspected right away. This light may come
on if the brake fluid is low. See
Brake Fluid
0 318.
If the light comes on while driving, pull off
the road and stop carefully. The brake pedal
might be harder to push, or the brake pedal
may go closer to the floor. It could take
longer to stop. If the light is still on, have
the vehicle towed for service. See
Transporting a Disabled Vehicle 0370.
{Warning
The brake system might not be working
properly if the brake system warning
light is on. Driving with the brake system
warning light on can lead to a crash.
If the light is still on after the vehicle has
been pulled off the road and carefully
stopped, have the vehicle towed for
service.
Electric Parking Brake Light
MetricEnglish
This light comes on when the parking brake
is applied. If the light continues flashing
after the parking brake is released, or while
driving, there is a problem with the Electric
Parking Brake system. A message may also
display in the Driver Information
Center (DIC).
If the light does not come on, or remains
flashing, see your dealer.
Service Electric Parking Brake
Light
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Instruments and Controls 125
Trailer Sway Control Light (Uplevel
Cluster)
This light will flash when Trailer Sway
Control is active. SeeTrailer Sway Control
(TSC) 0285.
Electronic Stability Control (ESC)
Off Light
This light comes on briefly when the vehicle
is turned on to show that the light is
working. If it does not come on then, have
it fixed so it will be ready to warn you if
there is a problem. This light comes on when the Electronic
Stability Control (ESC) system is turned off.
If ESC is off, the Traction Control System
(TCS) is also off. To turn ESC off and on, see
Traction Control/Electronic Stability Control
0
241.
If ESC and TCS are off, the systems do not
assist in controlling the vehicle. Adjust
driving accordingly.
Engine Coolant Temperature
Warning Light
This light comes on briefly while starting
the vehicle.
If it does not, have the vehicle serviced by
your dealer. If the system is working
normally the indicator light goes off.
Caution
The engine coolant temperature warning
light indicates that the vehicle has
overheated. Driving with this light on can
damage the engine and it may not be
covered by the vehicle warranty. See
Engine Overheating 0313.
The engine coolant temperature warning
light comes on when the engine has
overheated.
If this happens, pull over and let the engine
idle. See Engine Overheating 0313.
Driver Mode Control Light
This light comes on when Snow Mode is
selected.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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126 Instruments and Controls
This light comes on when Off-Road Mode is
selected.
This light comes on when the Tow/Haul
Mode is selected.
Tire Pressure Light
If equipped with the Tire Pressure Monitor
System (TPMS), this light comes on briefly
when the vehicle is started. It provides
information about tire pressures and
the TPMS.
When the Light Is On Steady
This indicates that one or more of the tires
are significantly underinflated.
A Driver Information Center (DIC) tire
pressure message may also display. Stop as
soon as possible, and inflate the tires to the
pressure value shown on the Tire and
Loading Information label. SeeTire Pressure
0 342.
When the Light Flashes First and Then Is On
Steady
If the light flashes for about a minute and
then stays on, there may be a problem with
the TPMS. If the problem is not corrected,
the light will come on every time the
vehicle is started. See Tire Pressure Monitor
Operation 0344.Engine Oil Pressure Light (Uplevel
Cluster)
Caution
Driving the vehicle with low engine oil
pressure can damage the engine and the
repairs would not be covered by the
vehicle warranty.
If the engine oil pressure light comes on
while driving:
1. Stop in a safe location and turn off the engine.
2. Check the oil level. See Engine Oil
0 306.
3. Add oil if the oil level is below the normal operating range.
4. Restart the vehicle. If the engine oil pressure light stays on for more
than 10 seconds, turn the vehicle
back off. Do not restart the vehicle.
See your dealer for service.
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Instruments and Controls 127
This light should come on briefly when the
engine starts. When the engine is off and
the vehicle is on, the light should remain
illuminated. If it does not come on under
either condition, contact your dealer.
If the light comes on and stays on when the
engine is running, it may not have adequate
oil pressure. The oil level may be low or
there may be some other oil system
problem. Turn the engine off when it is safe
to do so and contact your dealer.
Low Fuel Warning Light
A Low Fuel Warning Light near the fuel
gauge comes on briefly when the ignition is
turned on as a check to show it is working.It also comes on when the fuel gauge
indicator nears empty. The light turns off
when fuel is added. If it does not, have the
vehicle serviced.
Security Light
The security light should come on briefly as
the engine is started. If it does not come on,
have the vehicle serviced by your dealer.
If the system is working normally, the
indicator light turns off.
If the light stays on and the engine does
not start, there could be a problem with the
theft-deterrent system. See
Immobilizer
Operation 035.
High-Beam On Light
This light comes on when the high-beam
headlamps are in use. See Headlamp High/
Low-Beam Changer 0141.
IntelliBeam Light
This light comes on when the IntelliBeam
system, if equipped, is enabled. See Exterior
Lamp Controls 0139.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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128 Instruments and Controls
Front Fog Lamp Light
For vehicles with fog lamps, this light comes
on when the fog lamps are turned on.
The light goes out when the fog lamps are
turned off. SeeFog Lamps0143.
Lamps On Reminder
This light comes on when the exterior lamps
are in use, except when only the Daytime
Running Lamps (DRL) are active. See Exterior
Lamp Controls 0139.
Cruise Control Light
For vehicles with cruise control, the cruise
control light is white when the cruise
control is on and ready, and turns green
when the cruise control is set and active.
The light turns off when the cruise control is
turned off. See Cruise Control0244.
Door Ajar Light
This light comes on when a door is open or
not securely latched. Before driving, check
that all doors are properly closed.
Information Displays
Driver Information Center (DIC)
(Base Level)
The DIC displays are shown in the center of
the instrument cluster. The displays show
the status of many vehicle systems. The trip
odometer reset stem in the instrument
cluster is used to access the DIC menu
items.
If the vehicle has a diesel engine, see the
Duramax diesel supplement for more
information.
DIC Menu Items
Turn the trip odometer reset stem to scroll
through the following menu items:
.Digital Speedometer
.Trip 1/2
.Fuel Range
.Tire Pressure
.Remaining Oil Life
.Air Filter Life
.Brake Pad Life