ECU GMC SIERRA 2005 Repair Manual

Four-Wheel-Drive Vehicles
Use the following procedure to tow your vehicle:
1. Drive the vehicle up onto the tow dolly.
2. Shift an automatic transmission to PARK (P), or a
manual transmission to FIRST (1).
3. Turn the engine off, but leave the ignition on.4. Firmly set the parking brake.
5. Securely attach the vehicle being towed to
the tow dolly.
{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in Park (P) for
an automatic transmission, or if your vehicle is
in gear, for a manual transmission. You or
others could be injured. Make sure the parking
brake is rmly set before you shift the transfer
case to NEUTRAL.
6. Shift the transfer case to NEUTRAL. See
Four-Wheel Drive on page 2-37for the proper
procedure to select the neutral position for
your vehicle.
7. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle.
8. Turn the ignition off and lock the steering column.
4-65

Rear Towing (Rear Wheels Off
the Ground)
Two-Wheel-Drive Vehicles
Use the following procedure to tow your vehicle from
the rear:
1. Drive the vehicle onto the dolly.
2. Firmly set the parking brake. SeeParking Brake on
page 2-48.
3. Put an automatic transmission in PARK (P) or a
manual transmission in FIRST (1).
4. Follow the dolly manufacturer’s instructions to
attach and secure the vehicle being towed to
the dolly and then the loaded dolly to the tow
vehicle. Make sure the wheels are straight
before towing.
For manual transmission vehicles, make sure the
wheels are straight before proceeding to the
next steps. On automatic transmission vehicles, use
an adequeate clamping device to ensure that the
front wheels are locked into the straight position.
5. Release the parking brake only after the vehicle
being towed is rmly attached to the tow vehicle.
6. Turn the ignition to LOCK.
Four-Wheel-Drive Vehicles
Use the following procedure to tow your vehicle from
the rear:
1. Drive the vehicle onto the dolly.
2. Firmly set the parking brake. SeeParking Brake on
page 2-48.
3. Put an automatic transmission in PARK (P) or a
manual transmission in FIRST (1).
4. Follow the dolly manufacturer’s instructions to
attach and secure the vehicle being towed to
the dolly and then the loaded dolly to the tow
vehicle.
For manual transmission vehicles, make sure the
wheels are straight before proceeding to the
next steps. On automatic transmission vehicles, use
an adequeate clamping device to ensure that the
front wheels are locked into the straight position.
4-66

Driving with a Trailer
{CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon
monoxide (CO) could come into your vehicle.
You cannot see or smell CO. It can cause
unconsciousness or death. SeeEngine
Exhaust on page 2-53. To maximize your safety
when towing a trailer:
Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle. Do not use
the climate control setting for maximum air
because it only recirculates the air inside
your vehicle. SeeClimate Control System
on page 3-21.Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself 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 a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector, lamps,
tires and mirror adjustment. If the trailer has electric
brakes, start your vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your 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.
Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
4-88

If your vehicle is equipped with a low coolant sensor,
and the LOW COOLANT LEVEL message comes
on and stays on, it means you are low on engine
coolant. See “LOW COOLANT LEVEL” underDIC
Warnings and Messages on page 3-54.
Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixtureat the surge tank, but only when the
engine is cool.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight.
Coolant Surge Tank Pressure Cap
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 5-14for more
information on location.
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
You will nd a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-42.
In addition, you will nd an ENGINE OVERHEATED
and a REDUCED ENGINE POWER message in
the Driver Information Center (DIC) on the instrument
panel. SeeDIC Warnings and Messages on page 3-54.
5-37

Operating your vehicle with a light load means:
The total weight of occupants in your vehicle is less
than the total seating capacity number your vehicle
was designed to carry multiplied by 150 lbs (68 kg).
The total seating capacity number is on the Tire
and Loading Information label.
No more than 200 lbs (91 kg) of cargo, which must
be secured in the cargo area.
No trailer is attached to your vehicle.
You have not added any additional equipment to
your vehicle, like a truck cap or tool box.
The vehicle load capacity and the rear axle load
capacity are reduced when the tire pressure is lowered
to the amount recommended for improved ride.
Before operating your vehicle with passengers or cargo
greater than a light-load, you must inate the rear
tires to the recommended cold tire pressure shown on
the Tire and Loading Information Label. SeeLoading
Your Vehicle on page 4-50.
Dual Tire Operation
When the vehicle is new, or whenever a wheel, wheel
bolt or wheel nut is replaced, check the wheel nut torque
after 100, 1,000 and 6,000 miles (160, 1 600 and
10 000 km) of driving. For proper torque and wheel nut
tightening information, seeRemoving the Spare Tire
and Tools on page 5-93.
The outer tire on a dual wheel setup generally wears
faster than the inner tire. Your tires will wear more
evenly and last longer if you rotate the tires periodically,
seeTire Inspection and Rotation on page 5-83. Also
seeScheduled Maintenance on page 6-4.
{CAUTION:
If you operate your vehicle with a tire that is
badly underinated, the tire can overheat. An
overheated tire can lose air suddenly or catch
re. You or others could be injured. Be sure all
tires (including the spare) are properly inated.
SeeInation - Tire Pressure on page 5-79, for
information on proper tire ination.
5-82

Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km).
Any time you notice unusual wear, rotate your tires as
soon as possible and check wheel alignment. Also
check for damaged tires or wheels. SeeWhen It Is Time
for New Tires on page 5-85andWheel Replacement
on page 5-88for more information.
Make sure the spare tire is stored securely. Push, pull,
and then try to rotate or turn the tire. If it moves,
use the wheel wrench/hoist shaft to tighten the cable.
SeeChanging a Flat Tire on page 5-92.
If your vehicle has dual rear wheels, also seeDual Tire
Operation on page 5-82.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The rst rotation
is the most important. SeeScheduled Maintenance
on page 6-4.If your vehicle has single rear wheels and the tread
design for your front tires is the same as your rear tires,
use the rotation pattern shown here when rotating
your tires. If your vehicle is an SS model, the spare tire
is not designed to be used in the tire rotation.
5-83

Tire Chains
{CAUTION:
If your vehicle has dual wheels or P265/75R16,
LT265/75R16, P265/70R17 or P275/55R20 size
tires, don’t use tire chains. They can damage
your vehicle because there’s 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
CAUTION: (Continued)
CAUTION: (Continued)
instructions. To help avoid damage to your
vehicle, drive slowly, readjust or remove the
device if it’s contacting your vehicle, and don’t
spin your 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 is equipped with a tire size other than
P265/75R16, LT265/75R16, P265/70R17 or
P275/55R20, 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. Don’t 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.
5-90

4. Make sure the jack head is positioned so that the
rear axle is resting securely between the grooves
that are on the jack head. Turn the wheel
wrench clockwise to raise the vehicle. Raise the
vehicle far enough off the ground so there is enough
room for the spare tire to t under the wheel well.5. Remove all the wheel
nuts and take off the
at tire.
{CAUTION:
Rust or dirt on the wheel, or on the parts to
which it is fastened, can make the wheel nuts
become loose after a time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
the 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 you need to, to
get all the rust or dirt off. Rear Position
5-101

To release the spare tire from the secondary latch, do
the following:
1. Check under the vehicle to see if the cable
end is visible.
If the cable is not visible proceed to Step 6.
2. If it is visible, rst try to tighten the cable by
turning the wheel wrench clockwise until you
hear two clicks or feel it skip twice. You cannot
overtighten the cable.
3. Loosen the cable by turning the wrench
counterclockwise three or four turns.4. Repeat this procedure at least two times. If the
spare tire lowers to the ground, continue with
Step 5 ofRemoving the Spare Tire and Tools on
page 5-93.
5. 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.
5-106

3. Attach the wheel wrench (H) and extensions (I)
together.
4. Insert the hoist end (F)
through the hole (G) in
the rear bumper
and into the
hoist shaft.5. Raise the tire part way upward. Make sure the
retainer is seated in the wheel opening.
6. Raise the tire fully against the underside of the
vehicle by turning the wheel wrench clockwise
until you hear two clicks or feel it skip twice.
You cannot overtighten the cable.
7. Make sure the tire is stored securely. Push, pull, (A)
and then try to turn (B) the tire. If the tire moves,
use the wheel wrench to tighten the cable.
8. Reinstall the spare tire lock (if equipped).
5-111