ignition GMC SIERRA 2007 Workshop Manual

Turn the right knob to select the defog or
defrost mode.
-(Defog):This mode clears the windows of fog
or moisture and warm the passengers. The air
is directed to the windshield, oor outlets, and side
window vents.
0(Defrost):This mode removes fog or frost
from the windshield more quickly. A portion of the
air is directed to the windshield and the side
window vents, with some air directed to the oor
vents. The system will automatically force
outside air into the vehicle.
The recirculation mode cannot be selected in the
defog or defrost mode. When either mode is
selected, the system runs the air conditioning
compressor, unless the outside temperature
is close to freezing. Do not drive the vehicle until
all the windows are clear.
Rear Window Defogger
If your vehicle has a rear window defogger it uses a
warming grid to remove fog from the rear window.
The rear window defogger will only work when the
ignition is in RUN.
<(Rear):Press this button to turn the rear
window defogger on or off. An indicator light on
the button will come on to let you know that
the rear window defogger is activated.
The rear window defogger will only work when the
ignition is in RUN. The rear window defogger
will stay on for approximately 10 minutes after the
button is pressed, unless the ignition is turned
to ACC or LOCK. The defogger can also be turned
off by pressing the button again or by turning off
the engine.
Notice:Do not use anything sharp on the
inside of the rear window. If you do, you could
cut or damage the warming grid, and the
repairs would not be covered by your warranty.
Do not attach a temporary vehicle license,
tape, a decal or anything similar to the
defogger grid.
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The recirculation mode cannot be used with oor,
defog, or defrost modes. If recirculation is selected
with one of those modes, the indicator light will ash
three times and then turn off. The air conditioning
compressor will also come on when this mode is
activated. While in recirculation mode the windows
may fog when the weather is cold and damp. To
clear the fog, select either the defog or defrost
mode and increase the fan speed.
The recirculation mode can be turned off by
pressing the outside air button, or by turning off
the ignition.
;(Outside Air):Press this button to turn on
the outside air mode. When this mode is selected,
air from outside the vehicle will circulate
throughout your vehicle. An indicator light on the
button will come on to let you know that it is
activated. The outside air mode can be used
with all modes, but it cannot be used with
the recirculation mode.
Air Conditioning
#
(Air Conditioning):Press this button to turn
the air conditioning (A/C) compressor on and
off. When air conditioning is selected, an indicator
light comes on to let you know that the air
conditioning has been activated.
Pressing this button when the outside temperature
is too cool for air conditioning makes the air
conditioning indicator ash three times and then
turn off to let you know the air conditioning mode is
not available. If the air conditioning is on and
the outside temperature drops below a
temperature which is too cool for air conditioning
to be effective, the air conditioning light turns
off to let you know the air conditioning mode has
been canceled.
On hot days, open the windows long enough to let
hot inside air escape. This helps to reduce the
time it takes for the vehicle to cool down. It also
helps the system to operate more efficiently.
The air conditioning system removes moisture from
the air, so you might notice a small amount of
water dripping underneath the vehicle while idling
or after turning off the engine. This is normal.
242

Speedometer and Odometer
Your speedometer lets you see your speed in both
miles per hour (mph) and kilometers per hour
(km/h). Your odometer shows how far your vehicle
has been driven, in either miles (used in the United
States) or kilometers (used in Canada).
Engine Hour Meter Display
The Driver Information Center (DIC) can also
display the number of hours the engine has run.
To display the engine hours, turn the ignition
off, press and hold the reset button for at least
four seconds. The hour meter will be displayed for
up to 30 seconds, or until the ignition is turned
on. SeeDIC Operation and Displays (With
DIC Buttons) on page 268orDIC Operation and
Displays (Without DIC Buttons) on page 275
for more information.
Trip Odometer
The trip odometer can tell you how far your
vehicle has been driven since you last set the trip
odometer to zero.
Press the reset button, located on the instrument
panel cluster next to the voltmeter, to toggle
between the trip odometer and the regular
odometer. Holding the reset button for
approximately one second while the trip odometer
is displayed will reset it.
To display the odometer reading with the ignition
off, press the reset button.
SeeDIC Operation and Displays (With DIC
Buttons) on page 268orDIC Operation and
Displays (Without DIC Buttons) on page 275for
more information.
Tachometer
Your tachometer displays the engine speed in
revolutions per minute (rpm). See “Grade Braking
(Allison Transmission
®)” underTow/Haul Mode
on page 144for more information.
248

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 sensors, the airbag modules, the wiring and
the crash sensing and diagnostic module and, if
equipped, the passenger sensing system. For more
information on the airbag system, seeAirbag
System on page 83.
This light will come on
when you start your
vehicle, and it will ash
for a few seconds.
This means the system
is ready.
If the airbag readiness light stays on after the
vehicle is started or comes on while you are
driving, the airbag system may not be working
properly. Have your vehicle serviced right away.
Airbag Off Light
If your vehicle has an airbag on-off switch, it also
has a passenger airbag status indicator located
in the overhead console.
When the ignition key is turned to RUN or START,
the passenger airbag status indicator ON and
OFF, or the symbol for on and off, will light
for several seconds as a system check. Then,
after several more seconds, the status indicator
ON or OFF, or either the on or off symbol, will light
to let you know the status of the right front
passenger’s frontal airbag.
When you manually turn the right front passenger’s
airbag off using the airbag on-off switch in the
glove box, the indicator light OFF or the off symbol
will come on and stay on to remind you that the
airbag has been turned off.
United StatesCanada
250

Voltmeter Gage
Your vehicle may have
a voltmeter gage.
When the ignition is in RUN, this gage indicates
the battery voltage.
When the engine is running, this gage shows the
condition of the charging system. The gage
may 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, thecharging system light will come on. SeeCharging
System Light on page 254for more information.
The voltmeter gage may also read lower when in
fuel economy mode. This is normal.
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.
255

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 528for more
information.This light should come on briey when you turn
the ignition key to RUN. If it does not come
on then, have it xed so it will be ready to warn
you if there is a problem.
{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.
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 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 439.
United StatesCanada
256

Anti-Lock Brake System
Warning Light
With the Anti-Lock
Brake System (ABS),
this light will come on
when you start your
engine and may stay on
for several seconds.
That is normal. If the light does not come on then,
have it xed so it will be ready to warn you if
there is a problem.If the light stays on, or comes on when you are
driving, your vehicle needs service. A chime
will sound when the light stays on. If the regular
brake system warning light is not on, you still have
brakes, but you do not have ABS. If the regular
brake system warning light is also on you do
not have ABS and there is a problem with your
regular brakes. In addition to both lights, you
will also hear a chime sound on the rst
occurrence of a problem and each time the
vehicle is shut off and then restarted. SeeBrake
System Warning Light on page 256.
The ABS warning light should come on briey
when you turn the ignition key to RUN. If the light
does not come on then, have it xed so it will
be ready to warn you if there is a problem.
257

Tire Pressure Light
This light comes on
briey when you turn
the ignition to RUN.
This light will also come on when one or more of
your tires are signicantly underinated.A CHECK TIRE PRESSURE message in the
Driver Information Center (DIC) will accompany
the light. SeeDIC Warnings and Messages
on page 279for more information.
Stop and check your tires as soon as it is safe to
do so. If underinated, inate to the proper
pressure. SeeTires on page 550for more
information.
This light will ash for approximately 60 seconds
and then stay on if a problem is detected with
the Tire Pressure Monitor system.
SeeTire Pressure Monitor System on page 561
for more information.
259

Malfunction Indicator Lamp
Check Engine Light
Your vehicle has a
computer which
monitors operation of the
fuel, ignition, and
emission control
systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended
to assure that emissions are at acceptable
levels for the life of the vehicle, helping to produce
a cleaner environment. The check engine light
comes on to indicate that there is a problem and
service is required. Malfunctions often will be
indicated by the system before any problem is
apparent. This may prevent more serious damage
to your vehicle. This system is also designed to
assist your service technician in correctly
diagnosing any malfunction.Notice:If you keep driving your vehicle with
this light on, after awhile, the emission controls
might not work as well, your vehicle’s fuel
economy might not be as good, and the engine
might not run as smoothly. This could lead
to costly repairs that might not be covered by
your warranty.
Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system
of your vehicle or the replacement of the
original tires with other than those of the same
Tire Performance Criteria (TPC) can affect
your vehicle’s emission controls and can cause
this light to come on. Modications to these
systems could lead to costly repairs not
covered by your warranty. This could also
result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 486.
260

This light should come on, as a check to show
you it is working, when the ignition is on and the
engine is not running. If the light does not
come on, have it repaired. This light will also
come on during a malfunction in one of two ways:
Light Flashing— A misre condition has
been detected. A misre increases vehicle
emissions and may damage the emission
control system on your vehicle. Diagnosis and
service may be required.
Light On Steady— An emission control
system malfunction has been detected on your
vehicle. Diagnosis and service may be
required.
If the Light is Flashing
The following may prevent more serious damage
to your vehicle:
Reducing vehicle speed
Avoiding hard accelerations
Avoiding steep uphill grades
If you are towing a trailer, reduce the amount
of cargo being hauled as soon as it is
possibleIf the light stops ashing and remains on steady,
see “If the Light Is On Steady” following.
If the light continues to ash, when it is safe to do
so, stop the vehicle. Find a safe place to park
your vehicle. Turn the key off, wait at least
10 seconds and restart the engine. If the light
remains on steady, see “If the Light Is On Steady”
following. If the light is still ashing, follow the
previous steps, and see your dealer for service as
soon as possible.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully
install the cap. SeeFilling the Tank on page 493.
The diagnostic system can determine if the
fuel cap has been left off or improperly installed. A
loose or missing fuel cap will allow fuel to
evaporate into the atmosphere. A few driving trips
with the cap properly installed should turn the
light off.
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