2012 CHEVROLET SUBURBAN ECU

Black plate (25,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Driving and Operating 9-25
Notice:Cranking the engine for
long periods of time, by returning
the key to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down.
2. If the engine does not start
after 5‐10 seconds, especially in
very cold weather (below −18°C
or 0°F), it could be flooded with
too much gasoline. Try pushing
the accelerator pedal all the way
to the floor and holding it there
as you hold the key in START
for up to a maximum of
15 seconds. Wait at least
15 seconds between each try, to
allow the cranking motor to cool
down. When the engine starts,
let go of the key and accelerator. If the vehicle starts briefly but
then stops again, repeat these
steps. This clears the extra
gasoline from the engine. Do not
race the engine immediately
after starting it. Operate the
engine and transmission gently
until the oil warms up and
lubricates all moving parts.
Notice: The engine is designed to
work with the electronics in the
vehicle. If you add electrical
parts or accessories, you could
change the way the engine
operates. Before adding electrical
equipment, check with your
dealer. If you do not, the engine
might not perform properly. Any
resulting damage would not be
covered by the vehicle warranty.Engine Heater
The engine coolant heater can
provide easier starting and better
fuel economy during engine
warm-up in cold weather conditions
at or below −18°C (0°F). Vehicles
with an engine heater should be
plugged in at least four hours before
starting. An internal thermostat in
the plug-end of the cord may exist
which will prevent engine coolant
heater operation at temperatures
above −18°C (0°F).
To Use the Engine Coolant
Heater
1. Turn off the engine.
2. Open the hood and unwrap
the electrical cord. The cord
is secured to the Engine
Compartment Fuse Block with
a clip. Carefully remove the
wire tie which secures the
electrical cord. Do not cut the
electrical cord.

Black plate (67,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Driving and Operating 9-67
Driving with a Trailer
{WARNING
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.(Continued)
WARNING (Continued)
.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 9‑29.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.
Before starting, check all trailer
hitch parts and attachments,
safety chains, electrical connectors,
lamps, tires and mirrors. If the trailer has electric brakes, start the
combination moving and then
apply the trailer brake controller by
hand to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy
braking and sudden turns.
Passing
More passing distance is
needed when towing a trailer. The
combination will not accelerate
as quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.

Black plate (86,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
9-86 Driving and Operating
Say, for example, you have a 318 kg
(700 lb) snow plow. The total weight
of all occupants and cargo inside
the cab should not exceed 135 kg
(300 lb). This means that you may
only be able to carry one passenger.
But, even this may be too much if
there is other equipment already
adding to the weight of the vehicle.
Here are some guidelines for safely
carrying a snow plow on the vehicle:
.Make sure the weight on the
front and rear axles does not
exceed the axle rating for each.
.For the front axle, if more cargo
or passengers must be carried,
appropriate counter ballast must
be installed rear of the rear axle.
Counter ballast must be properly
secured so it will not move
during driving.
.Follow the snow plow
manufacturer's
recommendations regarding
rear ballast. Rear ballast may be
required to ensure a proper front
and rear weight distribution ratio,
even though the actual weight at
the front axle may be less than
the front axle rating.
.The snow plow manufacturer
or installer can assist in
determining the amount of rear
ballast required, to help make
sure the snowplow/vehicle
combination does not exceed
the GVW rating, the front and
rear axle ratings, and the front
and rear weight distribution ratio.
.The total vehicle must not
exceed the GVW rating.Front axle reserve capacity is the
difference between the front Gross
Axle Weight Rating (GAWR) and the
front axle weight of the vehicle with
full fuel and passengers. Basically, it
is the amount of weight that can be
added to the front axle before
reaching the front GAWR.
The front axle reserve capacity
for the vehicle can be found
in the lower right corner of the
Certification/Tire label, as shown.

Black plate (19,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-19
4. With the coolant surge tankpressure cap off, start the
engine and let it run until the
upper radiator hose can be felt
getting hot. Watch out for the
engine cooling fan.
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
fill 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
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge on your vehicle's instrument
panel. See Engine Coolant
Temperature Gauge on page 5‑14. In addition, ENGINE OVERHEATED
STOP ENGINE, ENGINE
OVERHEATED IDLE ENGINE, and
an ENGINE POWER IS REDUCED
message comes on in the Driver
Information Center (DIC) on the
instrument panel. See
Engine
Cooling System Messages on
page 5‑37 andEngine Power
Messages on page 5‑39.
If the decision is made not to lift the
hood when this warning appears,
but instead get service help right
away. See Roadside Assistance
Program (U.S. and Canada) on
page 13‑7 orRoadside Assistance
Program (Mexico) on page 13‑9.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.

Black plate (64,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-64 Vehicle Care
Used Replacement Wheels
{WARNING
Replacing a wheel with a used
one is dangerous. How it has
been used or how far it has been
driven may be unknown. It could
fail suddenly and cause a crash.
When replacing wheels, use a
new GM original equipment
wheel.
Tire Chains
If your vehicle is a Hybrid, see the
Hybrid Supplement for more
information.
{WARNING
If the vehicle has P265/65R18 or
P275/55R20 size tires, do not use
tire chains. There is not enough
clearance. Tire chains used on a
vehicle without the proper amount(Continued)
WARNING (Continued)
of clearance can cause damage
to the brakes, suspension,
or other vehicle parts. The area
damaged by the tire chains could
cause loss of control and a crash.
Use another type of traction
device only if its manufacturer
recommends it for the vehicle's
tire size combination and
road conditions. Follow that
manufacturer's instructions. To
avoid vehicle damage, drive
slow and readjust or remove the
traction device if it is contacting
the vehicle. Do not spin the
wheels.
If traction devices are used, install
them on the rear tires. Notice:
If the vehicle has
P265/70R17 size tires, use tire
chains only where legal and only
when necessary. Use chains that
are the proper size for the tires.
Install them on the rear tires only.
Do not use chains on the front
tires.
Tighten them as tightly as
possible with the ends securely
fastened. Drive slowly and
follow the chain manufacturer's
instructions. If the chains contact
the 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 the
vehicle.

Black plate (76,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-76 Vehicle Care
Make sure the retainer is fully
seated across the underside of
the wheel.
3. Assemble the two jack handleextensions (D) and wheel
wrench (E) as shown.
4. Insert the open end of theextension (J) through the hole in
the rear bumper (I) (hoist shaft
access hole).
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. The
cable cannot be overtightened.
7. Make sure the tire is storedsecurely. 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.
9. Reinstall the hoist shaft access cover.

Black plate (77,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-77
To store the tools, do the following:
A. Wheel Blocks
B. Tool Bag with Jack Tools
C. Retaining Bracket
D. Wing Nut Retaining Tool Bag
E. Jack
F. Wing Nut Retaining WheelBlocks
G. Jack Knob
1. Return the tools (wheel wrench, jack handle, and jack handle
extensions) to the tool bag (B). 2. Assemble wheel blocks (A) and
jack (E) together with the
wing nut (F).
3. Position the jack (E) and wheel blocks (A) in the driver side trim
panel over the wheelhouse.
4. Turn the jack knob (G) clockwise until the jack is secured tight in
the mounting bracket. Be sure to
position the holes in the base of
the jack onto the pin in the
mounting bracket.
5. Use the retaining bracket (C) to fasten the tool bag (B) on the
stud and turn the wing nut (D)
clockwise to secure.
6. Return the storage tray to itsoriginal stored position.

Black plate (79,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-79
3. Loosen the cable by turning thewrench 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 under “Removing the
Spare Tire and Tools” underTire
Changing on page 10‑66.
5. If the spare does not lower, turn the wrench counterclockwise
until approximately 15 cm (6 in)
of cable is exposed.
6. Stand the wheel blocks on their shortest ends, with the backs
facing each other.
A. Jack
B. Wheel Blocks
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.