2009 CHEVROLET TAHOE brake

Trailer Brake Control Panel
A. Manual Trailer Brake Apply Lever
B. Trailer Gain Adjustment ButtonsThe ITBC system has a control panel located on the
instrument panel to the left of the steering column. See
Instrument Panel Overview on page 3-4for more
information on location. The control panel allows
adjustment the amount of output, referred to as trailer
gain, available to the electric trailer brakes and
allows manual application the trailer brakes. The Trailer
Brake Control Panel is used along with the Trailer
Brake Display Page on the DIC to adjust and display
power output to the trailer brakes.
Trailer Brake DIC Display Page
The ITBC system displays messages into the vehicle’s
Driver Information Center (DIC). SeeDIC Warnings
and Messages on page 3-64for more information.
The display page indicates Trailer Gain setting, power
output to the electric trailer brakes, trailer connection
and system operational status.
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A. Trailer Gain Setting
B. Power Output to Trailer Brakes
C. No trailer with electric brakes connected or fault
presentThe Trailer Brake Display Page can be displayed by
performing any of the following actions:
Scrolling through the DIC menu pages using the
odometer trip stem or the DIC Vehicle Information
button (if equipped).
Pressing a Trailer Gain button – If the Trailer Brake
Display Page is not currently displayed, pressing a
Trailer Gain button will rst recall the current
Trailer Gain setting. After the Trailer Brake Display
Page is displayed, each press and release of
the gain buttons will then cause the Trailer Gain
setting to change.
Activating the Manual Trailer Brake Apply lever
Connecting a trailer equipped with electric trailer
brakes
All DIC warning and service messages must rst be
acknowledged by the driver by pressing the odometer
trip stem or the DIC Vehicle Information button (if
equipped) before the Trailer Brake Display Page can be
displayed and Trailer Gain can be adjusted.
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TRAILER GAIN – This setting is displayed anytime the
Trailer Brake Display Page is active. This setting
can be adjusted from 0.0 to 10.0 with either a trailer
connected or disconnected. To adjust the Trailer Gain,
press one of the Trailer Gain adjustment buttons
located on the Trailer Brake Control Panel. Press and
hold a gain button to cause the Trailer Gain to
continuously adjust. To turn the output to the trailer off,
adjust the Trailer Gain setting to 0.0 (zero).
0.0 (zero) gain is the factory default setting. To properly
adjust trailer gain, see the Trailer Gain Adjustment
Procedure later in this section.
TRAILER OUTPUT – This is displayed any time a trailer
with electric brakes is connected. Output to the electric
brakes is based on the amount of vehicle braking
present and relative to the Trailer Gain setting. Output is
displayed from 0 to 10 bars for each gain setting.
The Trailer Output will indicate “------’’ontheTrailer
Brake Display Page whenever the following occur:
No trailer is connected.
A trailer without electric brakes is connected (no
DIC message is displayed).
A trailer with electric brakes has become
disconnected (a CHECK TRAILER WIRING
message will also be displayed on the DIC).
There is a fault present in the wiring to the electric
trailer brakes (a CHECK TRAILER WIRING
message will also be displayed on the DIC).
There is a fault in the ITBC system (a SERVICE
TRAILER BRAKE SYSTEM message will also
be displayed in the DIC).
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.
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Trailer Gain Adjustment Procedure
Trailer Gain should be set for a specic 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. SeeLoading the Vehicle on page 4-33
for more information.3. After the electrical connection is made to a trailer
equipped with electric brakes:A TRAILER CONNECTED message will be
briey 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.
5. Drive the vehicle with the trailer attached on a level
road surface representative of the towing condition
and free of traffic at about 20 to 25 mph (32 to
40 km/h) and fully apply the Manual Trailer Brake
Apply lever.
Adjusting trailer gain at speeds lower than 20 to
25 mph (32 to 40 km/h) may result in an incorrect
gain setting.
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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 briey
displayed when a trailer with electric brakes is rst
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 rst 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.
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To determine if the electrical fault is on the vehicle side
or trailer side of the trailer wiring harness connection,
do the following:
1. Disconnect the trailer wiring harness from the
vehicle.
2. Turn the ignition OFF.
3. Wait ten seconds, then turn the ignition back to RUN.
4. If the CHECK TRAILER WIRING message
re-appears, the electrical fault is on the vehicle side.
If the CHECK TRAILER WIRING message only
re-appears when connecting the trailer wiring
harness to the vehicle, the electrical fault is on the
trailer side.
SERVICE TRAILER BRAKE SYSTEM – This message
will be displayed when there is a problem with the
ITBC system. If this message persists over multiple
ignition cycles there is problem with the ITBC system.
Take the vehicle to an authorized dealer/retailer to have
the ITBC system diagnosed and repaired.If either the CHECK TRAILER WIRING or SERVICE
TRAILER BRAKE SYSTEM message is displayed while
driving the vehicle, power is no longer available to
the trailer brakes. When traffic conditions allow, carefully
pull the vehicle over to the side of the road and turn
the ignition off. Check the wiring connection to the
trailer and turn the ignition back on. If either of these
messages continues, either the vehicle or trailer needs
service.
An authorized dealer/retailer may be able to diagnose
and repair problems with the trailer. However, any
diagnosis and repair of the trailer is not covered under
the vehicle warranty. Please contact your trailer
dealer for assistance with trailer repairs and trailer
warranty information.
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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.
CAUTION: (Continued)
CAUTION: (Continued)

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 2-50.
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.
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Driving On Grades
Reduce speed and shift to a lower gearbefore
starting down a long or steep downgrade. If the
transmission is not shifted down, the brakes might have
to be used so much that they would get hot and no
longer work well.
Vehicles can tow in D (Drive). Shift the transmission to
a lower gear if the transmission shifts too often under
heavy loads and/or hilly conditions.
The tow/haul mode may be used if the transmission
shifts too often. SeeTow/Haul Mode Light on page 3-49.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If the engine is
turned off immediately after towing at high altitude on
steep uphill grades, the vehicle may show signs similar to
engine overheating. To avoid this, let the engine run while
parked, preferably on level ground, with the automatic
transmission in P (Park) for a few minutes before turning
the engine off. If the overheat warning comes on, see
Engine Overheating on page 5-34.
Parking on Hills
{CAUTION:
Parking the vehicle on a hill with the trailer
attached can be dangerous. If something goes
wrong, the rig could start to move. People can be
injured, and both the vehicle and the trailer can be
damaged. When possible, always park the rig on a
at surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift into P (Park)
yet. Turn the wheels into the curb if facing downhill
or into traffic if facing uphill.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking
brake and shift into P (Park).
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