2012 CHEVROLET SUBURBAN lock

Black plate (82,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
9-82 Driving and Operating
Manual Trailer Brake Apply
The Manual Trailer Brake Apply
Lever is located on the Trailer
Brake Control Panel and is used to
apply the trailer’s electric brakes
independent of the vehicle’s brakes.
This lever is used in the Trailer Gain
Adjustment Procedure to properly
adjust the power output to the trailer
brakes. Sliding the lever to the left
will apply only the trailer brakes.
The power output to the trailer is
indicated in the Trailer Brake
Display Page in the DIC. If the
vehicle’s service brakes are applied
while using the Manual Trailer Brake
Apply Lever, the trailer output power
will be the greater of the two.
The trailer and the vehicle's brake
lamps will come on when either
vehicle braking or manual trailer
brakes are applied. Trailer Gain Adjustment Procedure
Trailer Gain should be set for a
specific trailering condition and
must be adjusted any time vehicle
loading, trailer loading or road
surface conditions change.
Setting the Trailer Gain properly is
needed for the best trailer stopping
performance. A trailer that is
over-gained may result in locked
trailer brakes. A trailer that is
under-gained may result in not
enough trailer braking. Both of these
conditions may result in poorer
stopping and stability of the vehicle
and trailer.
Use the following procedure to
correctly adjust Trailer Gain for each
towing condition:
1. Make sure the trailer brakes are
in proper working condition.
2. Connect a properly loaded trailer to the vehicle and make all
necessary mechanical and electrical connections. See
Vehicle Load Limits on
page 9‑16
for more information.
3. After the electrical connection is made to a trailer equipped with
electric brakes:
.A TRAILER CONNECTED
message will be briefly
displayed on the DIC
display.
.The Trailer Brake Display
Page will appear on the
DIC showing TRAILER
GAIN and TRAILER
OUTPUT.
.In the Trailer Output display
on the DIC, “- - - - - -“will
disappear if there is no
error present. Connecting
a trailer without electric
brakes will not clear the
six dashed lines.
4. Adjust the Trailer Gain by using the gain adjustment (+ / -)
buttons on the Trailer Brake
Control Panel.

Black plate (83,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Driving and Operating 9-83
5. Drive the vehicle with the trailerattached on a level road surface
representative of the towing
condition and free of traffic at
about 32 to 40 km/h (20 to
25 mph) and fully apply the
Manual Trailer Brake Apply
lever.
Adjusting trailer gain at speeds
lower than 32 to 40 km/h
(20 to 25 mph) may result in an
incorrect gain setting.
6. Adjust the Trailer Gain to just below the point of trailer wheel
lock-up, indicated by trailer
wheel squeal or tire smoke when
a trailer wheel locks.
Trailer wheel lock-up may not
occur if towing a heavily loaded
trailer. In this case, adjust the
Trailer Gain to the highest
allowable setting for the towing
condition. 7. Re-adjust Trailer Gain any time
vehicle loading, trailer loading or
road surface conditions change
or if trailer wheel lock-up is
noticed at any time while towing
Other ITBC Related DIC Messages
In addition to displaying TRAILER
GAIN and TRAILER OUTPUT
through the DIC, trailer connection
and ITBC system status is displayed
in the DIC.
TRAILER CONNECTED –This
message will be briefly displayed
when a trailer with electric brakes is
first connected to the vehicle. This
message will automatically turn off
in about ten seconds. The driver
can also acknowledge this message
before it automatically turns off.
CHECK TRAILER WIRING –This
message will be displayed if:
1. The ITBC system first
determines connection to a
trailer with electric brakes and
then the trailer harness becomes
disconnected from the vehicle. If the disconnect occurs while
the vehicle is stationary, this
message will automatically
turn off in about thirty seconds.
This message will also turn off if
the driver acknowledges this
message off or if the trailer
harness is re-connected.
If the disconnect occurs while
the vehicle is moving, this
message will continue until
the ignition is turned off. This
message will also turn off if
the driver acknowledges this
message off or if the trailer
harness is re-connected.
2. There is an electrical fault in the wiring to the electric trailer
brakes. This message will
continue as long as there is an
electrical fault in the trailer
wiring. This message will
also turn off if the driver
acknowledges this message off.

Black plate (1,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-3
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . . 10-7
Engine Oil Life System . . . . . . 10-9
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-11
Engine Air Cleaner/Filter . . . . 10-14
Cooling System . . . . . . . . . . . . 10-15
Engine Coolant . . . . . . . . . . . . . 10-16
Engine Overheating . . . . . . . . 10-19 Overheated Engine
Protection
Operating Mode . . . . . . . . . . . 10-21
Engine Fan . . . . . . . . . . . . . . . . . 10-21
Power Steering Fluid . . . . . . . 10-22
Washer Fluid . . . . . . . . . . . . . . . 10-23
Brakes . . . . . . . . . . . . . . . . . . . . . 10-24
Brake Fluid . . . . . . . . . . . . . . . . . 10-25
Battery . . . . . . . . . . . . . . . . . . . . . 10-26
Four-Wheel Drive . . . . . . . . . . . 10-27
Front Axle . . . . . . . . . . . . . . . . . . 10-27
Rear Axle . . . . . . . . . . . . . . . . . . 10-28
Starter Switch Check . . . . . . . 10-29
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-30
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-30
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-30
Wiper Blade Replacement . . . . . . . . . . . . . . 10-31
Glass Replacement . . . . . . . . 10-32
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-32
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-34
Halogen Bulbs . . . . . . . . . . . . . . 10-34
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-34
License Plate Lamp . . . . . . . . 10-35
Replacement Bulbs . . . . . . . . . 10-36
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-36
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-37
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-37
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-41
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-44
Tire Sidewall Labeling . . . . . . 10-45
Tire Designations . . . . . . . . . . . 10-47
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . 10-49
Tire Pressure . . . . . . . . . . . . . . . 10-52
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-53

Black plate (3,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-3
California
Proposition 65 Warning
Most motor vehicles, including this
one, contain and/or emit chemicals
known to the State of California to
cause cancer and birth defects or
other reproductive harm. Engine
exhaust, many parts and systems,
many fluids, and some component
wear by-products contain and/or
emit these chemicals.
California Perchlorate
Materials Requirements
Certain types of automotive
applications, such as airbag
initiators, seat belt pretensioners,
and lithium batteries contained in
Remote Keyless Entry transmitters,
may contain perchlorate materials.
Special handling may be necessary.
For additional information, see
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and
Modifications
Adding non‐dealer accessories or
making modifications to the vehicle
can affect vehicle performance and
safety, including such things as
airbags, braking, stability, ride and
handling, emissions systems,
aerodynamics, durability, and
electronic systems like antilock
brakes, traction control, and stability
control. These accessories or
modifications could even cause
malfunction or damage not covered
by the vehicle warranty.Damage to vehicle components
resulting from modifications or the
installation or use of non‐GM
certified parts, including control
module or software modifications, is
not covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
GM Accessories are designed to
complement and function with other
systems on the vehicle. See your
dealer to accessorize the vehicle
using genuine GM Accessories
installed by a dealer technician.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle on
page 3‑42.

Black plate (7,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-7
A.Engine Air Cleaner/Filter on
page 10‑14.
B. Coolant Surge Tank and Pressure Cap. See Cooling
System on page 10‑15.
C. Remote Positive (+) Terminal. See Jump Starting on
page 10‑82.
D. Battery on page 10‑26.
E. Remote Negative (−) Terminal (Out of View). See Jump
Starting on page 10‑82.
F. Automatic Transmission Dipstick (Out of View). See
“Checking the Fluid Level”
under Automatic Transmission
Fluid on page 10‑11.
G. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil on page 10‑7.
H. Engine Oil Dipstick (Out of View). See “Checking Engine
Oil” under Engine Oil on
page 10‑7. I. Engine Cooling Fan (Out of
View). See Cooling System on
page 10‑15.
J. Power Steering Fluid Reservoir. See Power Steering Fluid on
page 10‑22.
K. Brake Master Cylinder Reservoir. See “Brake Fluid”
under Brake Fluid on
page 10‑25.
L. Engine Compartment Fuse
Block on page 10‑37.
M. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10‑23.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.Engine Oil
To ensure proper engine
performance and long life, careful
attention must be paid to engine
oil. Following these simple, but
important steps will help protect
your investment:
.Always use engine oil approved
to the proper specification and of
the proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
.Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the
appropriate time. See Engine Oil
Life System on page 10‑9.
.Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.

Black plate (12,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-12 Vehicle Care
6. Using the TRANS TEMPreading, determine and
perform the appropriate check
procedure. If the TRANS TEMP
reading is not within the required
temperature ranges, allow the
vehicle to cool, or operate the
vehicle until the appropriate
transmission fluid temperature is
reached.
Cold Check Procedure
Use this procedure only as a
reference to determine if the
transmission has enough fluid
to be operated safely until a hot
check procedure can be made.
The hot check procedure is the
most accurate method to check the
fluid level. Perform the hot check
procedure at the first opportunity.
Use this cold check procedure
to check fluid level when the
transmission temperature is
between 27°C and 32°C
(80°F and 90°F).
1. Locate the transmission dipstick at the rear of the engine
compartment, on the passenger
side of the vehicle.
See Engine Compartment
Overview on page 10‑6 for more
information.
2. Flip the handle up, then pull out the dipstick and wipe it with a
clean rag or paper towel.
3. Install the dipstick by pushing it back in all the way; wait
three seconds, and then pull it
back out again.
4. Check both sides of the dipstick and read the lower level. Repeat
the check procedure to verify the
reading.5. If the fluid level is below theCOLD check band, add only
enough fluid as necessary to
bring the level into the COLD
band. It does not take much
fluid, generally less than 0.5 L
(1 pt). Do not overfill.
6. Perform a hot check at the first opportunity after the
transmission reaches a normal
operating temperature between
71°C to 93°C (160°F to 200°F).
7. If the fluid level is in the acceptable range, push the
dipstick back in all the way, then
flip the handle down to lock the
dipstick in place.

Black plate (13,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Vehicle Care 10-13
Hot Check Procedure
Use this procedure to check the
transmission fluid level when the
transmission fluid temperature
is between 71°C and 93°C
(160°F and 200°F).
The hot check is the most accurate
method to check the fluid level. The
hot check should be performed at
the first opportunity in order to verify
the cold check. The fluid level rises
as fluid temperature increases,
so it is important to ensure the
transmission temperature is within
range.
1. Locate the transmissiondipstick at the rear of the engine
compartment, on the passenger
side of the vehicle. See
Engine Compartment
Overview on page 10‑6 for
more information.
2. Flip the handle up, then pull out the dipstick and wipe it with a
clean rag or paper towel.
3. Install the dipstick by pushing it back in all the way; wait
three seconds, and then pull it
back out again.
4. Check both sides of the dipstick and read the lower level. Repeat
the check procedure to verify the
reading.5. Safe operating level is within theHOT cross hatch band on the
dipstick. If the fluid level is not
within the HOT band, and the transmission temperature is
between 71°C and 93°C
(160°F and 200°F), add or drain
fluid as necessary to bring the
level into the HOT band. If the
fluid level is low, add only
enough fluid to bring the level
into the HOT band. It does not
take much fluid, generally less
than 0.5 L (1 pt). Do not overfill.
6. If the fluid level is in the acceptable range, push the
dipstick back in all the way,
then flip the handle down to
lock the dipstick in place.
Consistency of Readings
Always check the fluid level at least
twice using the procedure described
previously. Consistency (repeatable
readings) is important to maintaining
proper fluid level. If readings are still
inconsistent, contact the dealer.

Black plate (18,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
10-18 Vehicle Care
{WARNING
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. They are
under pressure, and if you turn
the surge tank pressure
cap—even a little —they can
come out at high speed. Never
turn the cap when the cooling
system, including the surge tank
pressure cap, is hot. Wait for the
cooling system and surge tank
pressure cap to cool if you ever
have to turn the pressure cap. If no coolant is visible in the surge
tank, add coolant as follows:
1. Remove the coolant surge tank
pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot.
Turn the pressure cap slowly
counterclockwise about one full
turn. If a hiss is heard, wait for
that to stop. A hiss means there
is still some pressure left.
2. Keep turning the pressure cap slowly and remove it.
3. Fill the coolant surge tank with
the proper mixture to the FULL
COLD mark.