2008 GMC SAVANA climate control

Rear Heating System
Your vehicle may have a rear heating system that
allows you to adjust the amount of air flowing into
the rear of the vehicle, from the front-seating area.
This feature works with the main climate-control system
in your vehicle.
AUX:The thumbwheel for this system is located in the
switchbank below the audio system.
9(Fan):Turn the thumbwheel up or down to increase
or decrease the amount of heated air sent to the
rear-seating area.
Q(High):Turn the thumbwheel to this position to
supply the most amount of heat to the rear-seating area.
c(Medium):Turn the thumbwheel to this position to
supply half the amount of heat to the rear-seating area.
R(Low):Turn the thumbwheel to this position to
supply the least amount of heat to the rear-seating area.
9(Off):Turn the thumbwheel to this position to
turn the rear heating system off.
3-22

Rear Air Conditioning and Heating
System
Your vehicle may have a rear heating and
air-conditioning system. This system regulates the
temperature, the fan speed and the air delivery for
the rear-seat passengers only. It also works with
the main climate-control system in your vehicle.
Use this control panel when you would like to maintain
a separate temperature setting. Adjust the direction
of the airflow or adjust the fan speed for the rear seat
passenger(s).If your vehicle has a 135 inch (343 cm) wheelbase,
a rear control panel for this system is located in
the second row behind the driver in the rear of your
vehicle. A rear seat passenger can use this control panel
to personally adjust the temperature, the direction of
the airflow and the fan speed for the rear seating area.
The fan knob located on the front climate control
panel must be turned to AUX (Auxiliary) to let a rear
seat passenger use the control panel in the rear seating
area. Performing this action disables the front control
panel. To return control to this panel, move the fan knob
out of AUX.
9(Fan):Turn the left knob clockwise or
counterclockwise to increase or decrease the
fan speed in the rear-seating area.
9:This position turns the system off. Front Climate Control Panel
Rear Climate Control Panel
3-23

Mode Control:Turn the center knob clockwise or
counterclockwise to change the direction of the airflow
in the rear seating area.
To change the current mode, select one of the following:
H(Vent):This mode directs air to the upper outlets,
with a little air directed to the floor outlets.
2(Floor):This mode directs most of the air to the
floor outlets.
Temperature Control:Turn the right knob clockwise
or counterclockwise to increase or decrease the
temperature in the rear-seating area.
The air-conditioning system on the main climate control
panel must be turned on to direct cooled air to the
rear of the vehicle. If it is not on, then the temperature
in the rear of the vehicle remains at cabin temperature.
Be sure to keep the area under the front seats clear
of any objects so that the air inside of your vehicle can
circulate effectively.
For information on how to use the main climate control
system, seeClimate Control System on page 3-19.
For information on ventilation, seeOutlet Adjustment
on page 3-21.
Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages that
may be on your vehicle. The pictures will help you
locate them.
Warning lights and gages can signal that something
is wrong before it becomes serious enough to cause an
expensive repair or replacement. Paying attention to
your warning lights and gages could also save you
or others from injury.
Warning lights come on when there may be or is a
problem with one of your vehicle’s functions. As you
will see in the details on the next few pages, some
warning lights come on briefly when you start the engine
just to let you know they’re working. If you are familiar
with this section, you should not be alarmed when
this happens.
Gages can indicate when there may be or is a problem
with one of your vehicle’s functions. Often gages and
warning lights work together to let you know when
there’s a problem with your vehicle.
When one of the warning lights comes on and stays
on when you are driving, or when one of the gages shows
there may be a problem, check the section that tells you
what to do about it. Please follow this manual’s advice.
Waiting to do repairs can be costly – and even
dangerous. So please get to know your warning lights
and gages. They’re a big help.
3-24

To calibrate the compass, use the following procedure:
Compass Calibration Procedure
1. Before calibrating the compass, make sure the
compass zone is set to the variance zone in
which the vehicle is located. See “Compass
Variance (Zone) Procedure” earlier in this section.
Do not operate any switches such as window,
sunroof, climate controls, seats, etc. during
the calibration procedure.
2. Press the vehicle information button until
PRESS
VTO CALIBRATE COMPASS displays.
3. Press the set/reset button to start the compass
calibration.
4. The DIC will display CALIBRATING: DRIVE IN
CIRCLES. Drive the vehicle in tight circles at less
than 5 mph (8 km/h) to complete the calibration.
The DIC will display CALIBRATION COMPLETE
for a few seconds when the calibration is complete.
The DIC display will then return to PRESS
VTO
CALIBRATE COMPASS.
DIC Warnings and Messages
Messages are displayed on the DIC to notify the driver
that the status of the vehicle has changed and that some
action may be needed by the driver to correct the
condition. Multiple messages may appear one after
another.
Some messages may not require immediate action, but
you can press any of the DIC buttons on the instrument
panel to acknowledge that you received the messages
and to clear them from the display.
Some messages cannot be cleared from the DIC
display because they are more urgent. These messages
require action before they can be cleared. You should
take any messages that appear on the display seriously
and remember that clearing the messages will only
make the messages disappear, not correct the problem.
The following are the possible messages that can be
displayed and some information about them.
If your vehicle has the DURAMAX
®Diesel engine, see
the DURAMAX®Diesel manual for more information.
AUTOMATIC LIGHT CONTROL OFF
This message displays when the automatic headlamps
are turned off. SeeExterior Lamps on page 3-13for
more information.
3-49

SERVICE A/C SYSTEM
This message displays when the electronic sensors that
control the air conditioning and heating systems are
no longer working. Have the climate control system
serviced by your dealer/retailer if you notice a drop
in heating and air conditioning efficiency.
SERVICE AIR BAG
This message displays if there is a problem with
the airbag system. Have your dealer/retailer inspect
the system for problems. SeeAirbag Readiness Light on
page 3-27andAirbag System on page 1-57for more
information.
SERVICE BATTERY CHARGING
SYSTEM
On some vehicles, this message displays if there is a
problem with the battery charging system. Under certain
conditions, the charging system light may also turn
on in the instrument panel cluster. SeeCharging System
Light on page 3-32. Driving with this problem could
drain the battery. Turn off all unnecessary accessories.
Have the electrical system checked as soon as
possible. See your dealer/retailer.
SERVICE BRAKE SYSTEM
This message displays along with the brake system
warning light if there is a problem with the brake system.
SeeBrake System Warning Light on page 3-33. If this
message appears, stop as soon as possible and turn
off the vehicle. Restart the vehicle and check for
the message on the DIC display. If the message is still
displayed or appears again when you begin driving,
the brake system needs service as soon as possible.
See your dealer/retailer.
SERVICE STABILITRAK
If your vehicle has StabiliTrak®and this message
displays, it means there may be a problem with the
StabiliTrak
®system. If you see this message, try to
reset the system. Stop; turn off the engine for at least
15 seconds; then start the engine again. If this message
still comes on, it means there is a problem. You
should see your dealer/retailer for service. The vehicle
is safe to drive, however, you do not have the benefit
of StabiliTrak
®, so reduce your speed and drive
accordingly.
3-54

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 can not
see or smell CO. It can cause unconsciousness
or death. SeeEngine Exhaust on page 2-30.
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.
See Climate Control System in the Index.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.
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.
4-38

Uniform Tire Quality Grading
Quality grades can be found where applicable on
the tire sidewall between tread shoulder and
maximum section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration (NHTSA), which
grades tires by treadwear, traction, and
temperature performance. This applies only to
vehicles sold in the United States. The grades are
molded on the sidewalls of most passenger car
tires. The Uniform Tire Quality Grading (UTQG)
system does not apply to deep tread, winter-type
snow tires, space-saver, or temporary use spare
tires, tires with nominal rim diameters of
10 to 12 inches (25 to 30 cm), or to some
limited-production tires.
While the tires available on General Motors
passenger cars and light trucks may vary with
respect to these grades, they must also conform
to federal safety requirements and additional
General Motors Tire Performance Criteria (TPC)
standards.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified
government test course. For example, a tire
graded 150 would wear one and a half (1.5) times
as well on the government course as a tire
graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart significantly from the
norm due to variations in driving habits, service
practices, and differences in road characteristics
and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, are AA,
A, B, and C. Those grades represent the tire’s
ability to stop on wet pavement as measured under
controlled conditions on specified government test
surfaces of asphalt and concrete. A tire marked C
may have poor traction performance.
Warning
:The traction grade assigned to this
tire is based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
5-73

Fuse Usage
1 Climate Control 2 (HVAC)
2 Compass
3Ignition Switch, Theft Deterrent
System Module (PK3)
4 Upfitter Courtesy Lamps
5 Climate Control 1 (HVAC)
6 Empty
7 Instrument Panel Cluster
8 Audio System, Chime
9 Auxiliary Park Lamp
10 Auxiliary Trailer Back-up Lamps
11Remote Function Actuator,
Tire Pressure Monitor (TPM)
12 Climate Control (HVAC) Controls
13 Trailer Park Lamps
14 Front Park Lamps
15 Taillamps, Back-up Lamps
16 Empty
17 Steering Wheel Sensor
18 Outside Rearview Mirror Switch
19 Empty
20 Empty
21 Rear Defogger
22 Outside Rearview Mirror Heater
5-105