2009 GMC SIERRA service

Q:What if I added a snow plow? Will it keep the
airbags from working properly?
A:We have designed our airbag systems to work
properly under a wide range of conditions, including
snow plowing with vehicles that have the optional
Snow Plow Prep Package (RPO VYU). But do
not change or defeat the snow plow’s “tripping
mechanism.” If you do, it can damage your snow
plow and your vehicle, and it may cause an airbag
ination.
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.
Restraint System Check
Checking the Restraint Systems
Safety Belts
Now and then, check the safety belt reminder light,
safety belts, buckles, latch plates, retractors, and
anchorages are all working properly.
Look for any other loose or damaged safety belt system
parts that might keep a safety belt system from doing
its job. See your dealer/retailer to have it repaired. Torn
or frayed safety belts may not protect you in a crash.
They can rip apart under impact forces. If a belt is torn
or frayed, get a new one right away.
Make sure the safety belt reminder light is working.
SeeSafety Belt Reminders on page 3-36for more
information.
Keep safety belts clean and dry. SeeCare of Safety
Belts on page 5-116.
1-90

Airbags
The airbag system does not need regularly scheduled
maintenance or replacement. Make sure the airbag
readiness light is working. SeeAirbag Readiness Light
on page 3-37for more information.
Notice:If an airbag covering is damaged, opened, or
broken, the airbag may not work properly. Do not
open or break the airbag coverings. If there are any
opened or broken airbag covers, have the airbag
covering and/or airbag module replaced. For the
location of the airbag modules, seeWhat Makes an
Airbag Inflate? on page 1-79. See your dealer/retailer
for service.
Replacing Restraint System Parts
After a Crash
{CAUTION:
A crash can damage the restraint systems in your
vehicle. A damaged restraint system may not
properly protect the person using it, resulting in
serious injury or even death in a crash. To help
make sure your restraint systems are working
properly after a crash, have them inspected and any
necessary replacements made as soon as possible.If the vehicle has been in a crash, do you need new
safety belts or LATCH system (if equipped) parts?
After a very minor crash, nothing may be necessary.
But the safety belt assemblies that were used during any
crash may have been stressed or damaged. See your
dealer/retailer to have the safety belt assemblies
inspected or replaced.
If the vehicle has the LATCH system and it was being
used during a crash, you may need new LATCH
system parts.
New parts and repairs may be necessary even if the
safety belt or LATCH system (if equipped), was
not being used at the time of the crash.
If an airbag inates, you will need to replace airbag
system parts. See the part on the airbag system earlier
in this section.
Have the safety belt pretensioners checked if the
vehicle has been in a crash, if the airbag readiness light
stays on after the vehicle is started, or while you are
driving. SeeAirbag Readiness Light on page 3-37.
1-91

See your dealer/retailer if a replacement key or
additional key is needed.
Notice:If you ever lock your keys in the vehicle,
you may have to damage the vehicle to get in.
Be sure you have spare keys.
If you are locked out of the vehicle, call the Roadside
Assistance Center. SeeRoadside Assistance Program
on page 7-7.
Remote Keyless Entry (RKE)
System
If this vehicle has the Remote Keyless Entry (RKE)
system, it operates on a radio frequency subject
to Federal Communications Commission (FCC)
Rules and with Industry Canada.
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
1. This device may not cause interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.This device complies with RSS-210 of Industry Canada.
Operation is subject to the following two conditions:
1. This device may not cause interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization
to use this equipment.
If there is a decrease in the RKE operating range,
try this:Check the distance. The transmitter may be too far
from the vehicle. Stand closer during rainy or snowy
weather.
Check the location. Other vehicles or objects may be
blocking the signal. Take a few steps to the left or
right, hold the transmitter higher, and try again.
Check the transmitter’s battery. See “Battery
Replacement” later in this section.
If the transmitter is still not working correctly,
see your dealer/retailer or a qualied technician
for service.
2-4

The theft-deterrent system will not activate if the doors
are locked with the vehicle’s key or the manual door lock.
It activates only if you use the power door lock switch with
the door open or the RKE transmitter. You should also
remember that you can start your vehicle with the correct
ignition key if the alarm has been set off.
To avoid setting off the alarm by accident:
If you do not want to activate the theft-deterrent
system, the vehicle should be locked with the
door key after the doors are closed.
Always unlock a door with the RKE transmitter.
Unlocking a door any other way will set off the alarm
if the system has been armed.
If you set off the alarm by accident, press unlock on the
RKE transmitter or place the key in the ignition and
turn it to START to turn it off.
Testing the Alarm
To test the alarm:
1. From inside the vehicle, lower the driver’s window
and open the driver’s door.
2. Activate the system by locking the doors with the
RKE transmitter.
3. Get out of the vehicle, close the door and wait for
the security light to go out.
4. Then reach in through the window, unlock the door
with the manual door lock and open the door.
This should set off the alarm.
If the alarm does not sound when it should but the
headlamps ash, check to see if the horn works.
The horn fuse may be blown. To replace the fuse,
seeFuses and Circuit Breakers on page 5-122.
If the alarm does not sound or the headlamps do not
ash, see your dealer/retailer for service.
2-19

PASS-Key®III+ Electronic
Immobilizer
The PASS-Key III+ system operates on a radio
frequency subject to Federal Communications
Commission (FCC) Rules and with Industry Canada.
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation.
This device complies with RSS-210 of Industry Canada.
Operation is subject to the following two conditions:
1. This device may not cause interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization to
use this equipment.
PASS-Key III+ uses a radio frequency transponder in
the key that matches a decoder in the vehicle.
PASS-Key®III+ Electronic
Immobilizer Operation
Your vehicle has PASS-Key®III+ (Personalized
Automotive Security System) theft-deterrent system.
PASS-Key
®III+ is a passive theft-deterrent system.
The system is automatically armed when the key
is removed from the ignition.
The system is automatically disarmed when the key
is turned to ON/RUN, ACC/ACCESSORY or START
from the LOCK/OFF position.
You do not have to manually arm or disarm the system.
The security light will come on if there is a problem
with arming or disarming the theft-deterrent system.
When the PASS-Key
®III+ system senses that someone
is using the wrong key, it prevents the vehicle from
starting. Anyone using a trial-and-error method to start
the vehicle will be discouraged because of the high
number of electrical key codes.
If the engine does not start and the security light on
the instrument panel cluster comes on when trying to
start the vehicle, there may be a problem with your
theft-deterrent system. Turn the ignition off and try again.
2-20

If the engine still does not start, and the key appears to
be undamaged, try another ignition key. At this time, you
may also want to check the fuse, seeFuses and Circuit
Breakers on page 5-122. If the engine still does not start
with the other key, your vehicle needs service. If your
vehicle does start, the rst key may be faulty. See your
dealer/retailer who can service the PASS-Key
®III+ to
have a new key made. In an emergency, contact
Roadside Assistance.
It is possible for the PASS-Key
®III+ decoder to learn
the transponder value of a new or replacement key.
Up to 10 keys may be programmed for the vehicle.
The following procedure is for programming additional
keys only. If all the currently programmed keys are lost
or do not operate, you must see your dealer/retailer or
a locksmith who can service PASS-Key
®III+ to have
keys made and programmed to the system.
See your dealer/retailer or a locksmith who can service
PASS-Key
®III+ to get a new key blank that is cut
exactly as the ignition key that operates the system.To program the new additional key:
1. Verify that the new key has a
1stamped on it.
2. Insert the original, already programmed, key in the
ignition and start the engine. If the engine will not
start, see your dealer/retailer for service.
3. After the engine has started, turn the key to
LOCK/OFF, and remove the key.
4. Insert the new key to be programmed and turn it to
the ON/RUN position within ve seconds of turning
the ignition to the LOCK/OFF position in Step 3.
The security light will turn off once the key has been
programmed.
5. Repeat Steps 1 through 4 if additional keys are to
be programmed.
If you lose or damage your PASS-Key
®III+ key, see
your dealer/retailer or a locksmith who can service
PASS-Key
®III+ to have a new key made.
Do not leave the key or device that disarms or
deactivates the theft deterrent system in the vehicle.
2-21

The steering can bind with the wheels turned off center.
If this happens, move the steering wheel from right
to left while turning the key to ACC/ACCESSORY.
If this doesn’t work, then the vehicle needs service.
Notice:Using a tool to force the key to turn in
the ignition could cause damage to the switch or
break the key. Use the correct key, make sure it
is all the way in, and turn it only with your hand.
If the key cannot be turned by hand, see your
dealer/retailer.
B (ACC/ACCESSORY):This position lets things like the
radio and the windshield wipers operate while the engine
is off. Use this position if the vehicle must be pushed or
towed.
C (ON/RUN):This position can be used to operate the
electrical accessories and to display some instrument
panel cluster warning and indicator lights. The switch
stays in this position when the engine is running.
The transmission is also unlocked in this position on
automatic transmission vehicles.
If you leave the key in the ACC/ACCESSORY or ON/
RUN position with the engine off, the battery could be
drained. You may not be able to start the vehicle if the
battery is allowed to drain for an extended period of time.D (START):This is the position that starts the engine.
When the engine starts, release the key. The ignition
switch returns to ON/RUN for driving.
A warning tone will sound when the driver door is
opened, the ignition is in ACC/ACCESSORY or
LOCK/OFF and the key is in the ignition.
Retained Accessory Power (RAP)
The following vehicle accessories can be used for up to
10 minutes after the engine is turned off:
Audio System
Power Windows
OnStar®System (if equipped)
Sunroof (if equipped)
These features work when the key is in ON/RUN or
ACC/ACCESSORY. Once the key is turned from
ON/RUN to LOCK/OFF, the windows and sunroof
continue to work up to 10 minutes until any door
is opened. The radio continues to work for up to
10 minutes or until the driver door is opened.
2-23

Shifting In or Out of Neutral
1. With the vehicle running and the engine at an idle
set the parking brake.
2. Place the transmission into N (Neutral).
Shift the transfer case in one continuous motion into or
out of the N (Neutral) position.
Electronic Transfer Case
The transfer case knob is
located next to the
steering column.
Use the dial to shift into and out of four-wheel drive.
Recommended Transfer Case Settings
Driving ConditionsTransfer Case Settings
2m4m4nN
Normal YES
Severe YES
Extreme YES
Vehicle in Tow* YES
*SeeRecreational Vehicle Towing on page 4-45
Towing Your Vehicle on page 4-45
You can choose among four driving settings:
Indicator lights in the dial show which setting you are in.
The indicator lights will come on briey when you turn on
the ignition and one will stay on. If the lights do not come
on, you should take the vehicle to your dealer/retailer
for service. An indicator light ashes while shifting the
transfer case and remains illuminated when the shift is
complete. If for some reason the transfer case cannot
make a requested shift, it will return to the last chosen
setting.
2-41