ecu GMC SIERRA 1500 2009 Repair Manual

Four-Wheel-Drive Vehicles
Use the following procedure to dolly tow a
four-wheel-drive vehicle from the rear:
1. Attach the dolly to the tow vehicle following the
dolly manufacturer’s instructions.
2. Drive the rear wheels onto the dolly.
3. Firmly set the parking brake. SeeParking Brake on
page 2-50.
4. Put the transmission in P (Park).
5. Secure the vehicle to the dolly following the
manufacturer’s instructions.
6. Use an adequate clamping device designed for
towing to ensure that the front wheels are locked
into the straight position.{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer case
into N (Neutral) can cause the vehicle to roll even
if the transmission is in P (Park). The driver or
others could be injured. Make sure the parking
brake is rmly set before the transfer case is
shifted to N (Neutral).
7. Shift the transfer case to N (Neutral). See “Shifting
into Neutral” underFour-Wheel Drive on page 2-37
for the proper procedure to select the neutral
position for the vehicle.
8. Turn the ignition to LOCK/OFF.
After towing, see “Shifting Out of Neutral” under
Four-Wheel Drive on page 2-37.
4-52

Vehicle Axle Ratio Maximum Trailer Weight GCWR (a)
3500 Series 4WD Extended Cab (e)
6.0L V8 (Single Rear Wheels)3.73
4.109,600 lbs (4 355 kg)
12,100 lbs (5 489 kg)16,000 lbs (7 257 kg)
18,500 lbs (8 391 kg)
6.0L V8 (Dual Rear Wheels)3.73
4.109,200 lbs (4 173 kg)
11,700 lbs (5 307 kg)16,000 lbs (7 257 kg)
18,500 lbs (8 391 kg)
3500 Series 4WD Crew Cab (e)
6.0L V8 (Single Rear Wheels)3.73
4.109,400 lbs (4 264 kg)
11,900 lbs (5 398 kg)16,000 lbs (7 257 kg)
18,500 lbs (8 391 kg)
6.0L V8 (Dual Rear Wheels)3.73
4.109,100 lbs (4 128 kg)
11,600 lbs (5 262 kg)16,000 lbs (7 257 kg)
18,500 lbs (8 391 kg)
(a) The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle
and trailer including any passengers, cargo, equipment and conversions. The GCWR for the vehicle should not be
exceeded.
(b) Fifth-wheel or gooseneck kingpin weight 15 percent to 25 percent of trailer weight up to 1,500 lbs (680 kg)
maximum.
(c) This model is neither designed nor intended to tow fth-wheel or gooseneck trailers.
(d) Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,000 lbs
(1 361 kg) maximum.
(e) Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs
(1 587 kg) maximum.
Ask your dealer/retailer for our trailering information or advice, or write us at our Customer Assistance Offices.
SeeCustomer Assistance Offices on page 7-6for more information.
4-63

Driving with a Trailer
{CAUTION:
When towing a trailer, exhaust gases may collect
at the rear of the vehicle and enter if the liftgate,
trunk/hatch, or rear-most window is open.
Engine exhaust contains carbon monoxide (CO)
which cannot be seen or smelled. It can cause
unconsciousness and even death.
To maximize safety when towing a trailer:
Have the exhaust system inspected for leaks
and make necessary repairs before starting
a trip.
Never drive with the liftgate, trunk/hatch, or
rear-most window open.
Fully open the air outlets on or under the
instrument panel.
Adjust the Climate Control system to a setting
that brings in only outside air and set the fan
speed to the highest setting. See Climate
Control System in the Index.
For more information about carbon monoxide, see
Engine Exhaust on page 2-55.Towing a trailer requires a certain amount of experience.
Get to know the rig before setting out for the open
road. Get acquainted with the feel of handling and
braking with the added weight of the trailer. And always
keep in mind that the vehicle you are driving is now
longer and not as responsive as the vehicle is by itself.
Before starting, check all trailer hitch parts and
attachments, safety chains, electrical connectors, lamps,
tires and mirror adjustments. If the trailer has electric
brakes, start the vehicle and trailer moving and
then apply the trailer brake controller by hand to be sure
the brakes are working. This checks the electrical
connection at the same time.
During the trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer brakes
are still working.
While towing a trailer or when exposed to long periods
of sunshine, the oor of the truck bed may become
very warm. Avoid putting items in the truck bed
that might be affected by high ambient temperatures.
4-77

Maintenance When Trailer Towing
The vehicle needs service more often when pulling a
trailer. See this manual’s Maintenance Schedule
or Index for more information. Things that are especially
important in trailer operation are automatic transmission
uid, engine oil, axle lubricant, belts, cooling system
and brake system. It is a good idea to inspect
these before and during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The vehicle is equipped with one of the following wiring
harnesses for towing a trailer or hauling a slide-in
camper.
Basic Trailer Wiring
All regular, extended cab and crew cab pickups have a
seven-wire trailer towing harness.
For vehicles not equipped with heavy duty trailering, the
harness is secured to the vehicle’s frame behind the
spare tire mount. The harness requires the installation of
a trailer connector, which is available through your
dealer/retailer.
If towing a light-duty trailer with a standard four-way
round pin connector, an adapter is available from your
dealer/retailer.
4-81

4. With the coolant surge tank pressure cap off,
start the engine and let it run until the engine
coolant temperature gage indicates approximately
195°F (90°C).
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge
tank until the level reaches the FULL COLD mark.
5. Replace the pressure cap. Be sure the pressure
cap is hand-tight and fully seated.
6. Verify coolant level after engine is shut off and the
coolant is cold. If necessary, repeat coolant ll
procedure Steps 1 through 6.
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may occur.
Be sure the cap is properly and tightly secured.
Engine Overheating
If the vehicle has the DURAMAX®Diesel engine, see
the DURAMAX®Diesel manual for more information.
The vehicle has several indicators to warn of engine
overheating.
You will nd a coolant temperature gage on the vehicle’s
instrument panel. SeeEngine Coolant Temperature
Gage (US-Canada) on page 3-44.In addition, you will nd ENGINE OVERHEATED STOP
ENGINE, ENGINE OVERHEATED IDLE ENGINE,
and ENGINE POWER IS REDUCED messages in the
Driver Information Center (DIC) on the instrument panel.
SeeDIC Warnings and Messages on page 3-66.
You may decide not to lift the hood when this warning
appears, but instead get service help right away.
SeeRoadside Assistance Program on page 7-7.
If you do decide to lift the hood, make sure the vehicle
is parked on a level surface.
Then check to see if the engine cooling fans are
running. If the engine is overheating, both fans should
be running. If they are not, do not continue to run
the engine and have the vehicle serviced.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty.
SeeOverheated Engine Protection Operating Mode
on page 5-38for information on driving to a safe
place in an emergency.
Notice:If the engine catches re while driving
with no coolant, the vehicle can be badly damaged.
The costly repairs would not be covered by the
vehicle warranty. SeeOverheated Engine Protection
Operating Mode on page 5-38for information on
driving to a safe place in an emergency.
5-36

Bulb Replacement
For the proper type of replacement bulbs, see
Replacement Bulbs on page 5-66.
For any bulb changing procedure not listed in this
section, contact your dealer/retailer.
Halogen Bulbs
{CAUTION:
Halogen bulbs have pressurized gas inside and
can burst if you drop or scratch the bulb. You or
others could be injured. Be sure to read and follow
the instructions on the bulb package.
Headlamps
To replace one of these bulbs:
1. Open the hood. SeeHood Release on page 5-14
for more information.
2. If you are replacing the bulb on the passenger side
remove the Engine Air Cleaner cover. SeeEngine Air
Cleaner/Filter on page 5-22for more information.3. Reach in and access the bulb sockets from inside
the engine compartment.
4. Turn the bulb socket counterclockwise to remove it
from the headlamp assembly and pull it straight out.
5. Unplug the electrical connector from the old bulb by
releasing the clips on the bulb socket.
6. Replace it with a new bulb socket.
7. Plug in the electrical connector to the new bulb
socket.
8. Reinstall the new bulb socket into the headlamp
assembly and turn it clockwise to secure.
9. Close the hood.
5-61

If your vehicle has dual
rear wheels and the
tread design for the front
tires is different from the
dual rear tires, always
use the correct rotation
pattern shown here
when rotating the tires.
The dual tires are rotated as a pair, and the inside
rear tires become the outside rear tires.
When you install dual wheels, be sure the vent
holes in the inner and outer wheels on each side
are lined up.
After the tires have been rotated, adjust the front
and rear ination pressures as shown on the Tire
and Loading Information label. SeeInflation - Tire
Pressure on page 5-76andLoading the Vehicle on
page 4-34.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specifications on page 5-131.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
places where the wheel attaches to the
vehicle. In an emergency, you can use a cloth
or a paper towel to do this; but be sure to use a
scraper or wire brush later, if needed, to get all
the rust or dirt off. SeeChanging a Flat Tire on
page 5-94.
If your vehicle has a Tire Pressure Monitor
System (TPMS), reset the TPMS sensors after
rotating the tires. SeeTire Pressure Monitor
Operation on page 5-80.
Make sure the spare tire, if your vehicle has one,
is stored securely. Push, pull, and then try to
rotate or turn the tire. If it moves, tighten the cable.
SeeStoring a Flat or Spare Tire and Tools on
page 5-110.
5-85

Tire Chains
{CAUTION:
If your vehicle has dual wheels or P265/65R18,
P275/55R20 or LT265/70R17 size tires, do not
use tire chains. They can damage your vehicle
because there is not enough clearance. Tire
chains used on a vehicle without the proper
amount of clearance can cause damage to
the brakes, suspension, or other vehicle parts.
The area damaged by the tire chains could cause
you to lose control of your vehicle and you or
others may be injured in a crash.
Use another type of traction device only if its
manufacturer recommends it for use on your
vehicle and tire size combination and road
conditions. Follow that manufacturer’s instructions.
CAUTION: (Continued)
CAUTION: (Continued)
To help avoid damage to your vehicle, drive
slowly, readjust, or remove the device if it is
contacting your vehicle, and do not spin your
vehicle’s wheels.
If you do nd traction devices that will t, install
them on the rear tires.
Notice:If your vehicle does not have dual
wheels and has a tire size other than P265/65R18,
P275/55R20 or LT265/70R17, use tire chains only
where legal and only when you must. Use chains that
are the proper size for your tires. Install them on the
tires of the rear axle. Do not use chains on the tires
of the front axle. Tighten them as tightly as possible
with the ends securely fastened. Drive slowly and
follow the chain manufacturer’s instructions. If you
can hear the chains contacting your vehicle, stop and
retighten them. If the contact continues, slow down
until it stops. Driving too fast or spinning the wheels
with chains on will damage your vehicle.
5-92

4. Position the jack under the vehicle as shown. If the
at tire is on the front of the vehicle (1500 Model
vehicles), position the jack under the bracket
attached to the vehicle’s frame, behind the at tire.
If the at tire is on the front of the vehicle (all other
models), position the jack on the frame behind the
at tire.If the at tire is on the rear, for 1500 models
position the jack under the rear axle about
2 inches (5 cm) inboard of the shock absorber
bracket; for all other models, position the jack
under the rear axle between the spring anchor
and the shock absorber bracket.
If you have added a snow plow to the front of your
vehicle, lower the snow plow fully before raising
the vehicle.
Make sure that the jack head is positioned so
that the rear axle is resting securely between the
grooves that are on the jack head. Front Position - 1500
Models
Front Position - All
Other ModelsRear Position – 1500
ModelsRear Position – All
Other Models
5-102

5. If the spare does not lower, turn the wrench
counterclockwise until approximately 6 inches
(15 cm) of cable is exposed.
6. Stand the wheel blocks on their shortest ends, with
the backs facing each other.
7. Place the bottom
edge of the jack (A)
on the wheel blocks (B),
separating them so that
the jack is balanced
securely.
8. Attach the jack handle, extension, and wheel
wrench to the jack and place it (with the wheel
blocks) under the vehicle toward the front of the
rear bumper.
5-108