2008 GMC SAVANA PASSENGER cooling

Entry/Exit Lighting
Your vehicle has an illuminated entry/exit feature.
When a door is opened or the key is removed from
the ignition, the dome lamps will come on if the dome
override button is in the out position.
Reading Lamps
For vehicles with reading lamps, press the button
located next to each lamp to turn it on or off.
Your vehicle may also have reading lamps in other
locations. To turn each one on or off, press the button
located next to the lamp. The lamps cannot be adjusted.
Electric Power Management
The vehicle has Electric Power Management (EPM)
that estimates the battery’s temperature and state
of charge. It then adjusts the voltage for best
performance and extended life of the battery.
When the battery’s state of charge is low, the voltage is
raised slightly to quickly put the charge back in. When
the state of charge is high, the voltage is lowered slightly
to prevent overcharging. If the vehicle has a voltmetergage or voltage display on the Driver Information
Center (DIC), you may see the voltage move up or
down. This is normal. If there is a problem, an alert
will be displayed.
The battery can be discharged at idle if the electrical
loads are very high. This is true for all vehicles.
This is because the generator (alternator) may not
be spinning fast enough at idle to produce all the
power that is needed for very high electrical loads.
A high electrical load occurs when several of the
following loads are on: headlamps, high beams, rear
window defogger, climate control fan at high speed,
engine cooling fans, trailer loads, and loads plugged
into accessory power outlets.
EPM works to prevent excessive discharge of the battery.
It does this by balancing the generator’s output and the
vehicle’s electrical needs. It can increase engine idle
speed to generate more power, whenever needed.
Battery Run-Down Protection
This feature shuts off the dome lamps if they are left on
for more than 10 minutes when the ignition is in LOCK.
This will help prevent the battery from running down.
3-17

Climate Controls
Climate Control System
The heating, cooling, and ventilation for your vehicle
can be controlled with this system.
9(Fan):Turn the left knob clockwise or
counterclockwise to increase or decrease the fan speed.
Temperature Control:Turn the middle knob clockwise
or counterclockwise to increase or decrease the
temperature inside the vehicle.
Turn the right knob clockwise or counterclockwise to
direct the airflow inside of the vehicle.To change the current mode, select one of the following:
9(Off):This turns the system off.
H(Vent):This mode directs air to the instrument
panel outlets.
)(Bi-Level):This mode directs about half of the air
to the instrument panel outlets, then directs most of
the remaining air to the floor outlets. Some air may be
directed toward the windshield.
6(Floor):This mode directs most of the air to the
floor outlets with some air directed to the outboard
outlets (for the side windows) and some air directed
to the windshield.
The right knob can also be used to select the defrost
and defog modes. Information on defogging and
defrosting can be found later in this section.
3-19

If your vehicle has air conditioning, your heating/air
conditioning controls will look like this:
On hot days, open the windows to let hot inside air
escape; then close them. This helps to reduce the time
needed for the vehicle to cool down and the system
operates more efficiently.
#(Air Conditioning):This setting will begin to cool
and dehumidify the air inside of the vehicle.
V(Maximum Air Conditioning):Turn the right knob
to
Vfor maximum cooling. This setting cools the air the
fastest, by recirculating the inside air.
Defogging and Defrosting
Fog on the inside of windows is a result of high humidity
(moisture) condensing on the cool window glass. This
can be minimized if the climate control is used properly.
There are two modes to clear fog or frost from the
windshield and side windows.Use the defog mode to clear the windows of fog or
moisture and warm the passengers. Use the defrost
mode to remove fog or frost from the windshield more
quickly in extremely cold conditions. For best results,
clear all snow and ice from the windshield before
defrosting.
Turn the knob on the right of the climate control panel
to select the defog or defrost mode. The temperature
knob should be in the red area and the fan control
toward high.
-(Defog):With this setting, the outside air comes
out of both the floor and defroster outlets. Adjust the
temperature knob for warmer or cooler air. The air
conditioning compressor may operate in this setting
to dehumidify the air.
1(Defrost):This setting operates the defroster.
Most of the air comes out near the windshield,
with some going to the floor outlets and front side
windows. The air conditioning compressor may
operate in this setting to dehumidify the air.
Do not drive the vehicle until all the windows are clear.
3-20

Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority of the operation, the gage
will read 210°F (100°C) or less. If you are pulling a load
or going up hills, it is normal for the temperature to
fluctuate and approach the 250°F (122°C) mark. If the
gage reaches the 260°F (125°C) mark, it indicates
that the cooling system is working beyond its capacity.
SeeEngine Overheating on page 5-26.
Tire Pressure Light
This light comes on briefly
when the engine is started.
This light will also come on when one or more of your
tires are significantly underinflated.
A tire pressure message in the Driver Information
Center (DIC), may accompany the light. SeeDIC
Warnings and Messages on page 3-49for more
information.
Stop and check your tires as soon as it is safe to do so.
If underinflated, inflate to the proper pressure. SeeTires
on page 5-53for more information.
If a problem is detected with the Tire Pressure Monitor
System, this light will flash for approximately 60 seconds
and then stay on solid for the remainder of the ignition
cycle. SeeTire Pressure Monitor System on page 5-62
for more information. United States
Canada
3-35

ENGINE OVERHEATED STOP ENGINE
Notice:If you drive your vehicle while the engine
is overheating, severe engine damage may occur.
If an overheat warning appears on the instrument
panel cluster and/or DIC, stop the vehicle as soon
as possible. SeeEngine Overheating on page 5-26
for more information.
This message displays and a chime sounds if the
engine cooling system reaches unsafe temperatures for
operation. Stop and turn off the vehicle as soon as it
is safe to do so to avoid severe damage. This message
clears when the engine has cooled to a safe operating
temperature.
ENGINE POWER IS REDUCED
This message displays and a chime sounds when the
cooling system temperature gets too hot and the engine
further enters the engine coolant protection mode.
SeeEngine Overheating on page 5-26for further
information.
This message also displays when the vehicle’s engine
power is reduced. Reduced engine power can affect
the vehicle’s ability to accelerate. If this message is on,
but there is no reduction in performance, proceed toyour destination. The performance may be reduced
the next time the vehicle is driven. The vehicle may be
driven at a reduced speed while this message is on,
but acceleration and speed may be reduced. Anytime
this message stays on, the vehicle should be taken
to your dealer/retailer for service as soon as possible.
FUEL LEVEL LOW
This message displays if the fuel level is low. Refuel as
soon as possible. SeeFuel Gage on page 3-41and
Fuel on page 5-5for more information.
ICE POSSIBLE DRIVE WITH CARE
This message displays when the outside air temperature
is cold enough to create icy road conditions. Adjust
your driving accordingly.
LEFT REAR DOOR OPEN
On some vehicles, this message displays and a chime
sounds if the driver side rear door is not fully closed
and the vehicle is in a drive gear. Stop and turn off the
vehicle, check the door for obstructions, and close
the door again. Check to see if the message still
appears on the DIC.
3-52

Hill and Mountain Roads
Driving on steep hills or through mountains is different
than driving on flat or rolling terrain. Tips for driving
in these conditions include:
•Keep your vehicle serviced and in good shape.
•Check all fluid levels and brakes, tires, cooling
system, and transmission.
•Going down steep or long hills, shift to a
lower gear.
{CAUTION:
If you do not shift down, the brakes could get
so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Shift down
to let the engine assist the brakes on a steep
downhill slope.
{CAUTION:
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. The brakes will have
to do all the work of slowing down and they
could get so hot that they would not work well.
You would then have poor braking or even
none going down a hill. You could crash.
Always have the engine running and your
vehicle in gear when you go downhill.
•Stay in your own lane. Do not swing wide or cut
across the center of the road. Drive at speeds
that let you stay in your own lane.
•Top of hills: Be alert — something could be in your
lane (stalled car, accident).
•Pay attention to special road signs (falling rocks
area, winding roads, long grades, passing or
no-passing zones) and take appropriate action.
4-15

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.
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Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don’t overfill),
engine oil, axle lubricant, belt, cooling system and brake
system. Each of these is covered in this manual, and the
Index will help you find them quickly. If you’re trailering,
it’s a good idea to review these sections before you start
your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The optional heavy-duty trailer wiring package includes
a wiring harness, with a seven-pin connector at the
rear of the vehicle and a four-wire harness assembly
under the driver side of the instrument panel. The
four-wire harness assembly comes without a connector.
If your vehicle does not have a trailer hitch, the
seven-wire harness assembly with connector is taped
together and located in a frame pocket at the driver side
rear left corner of the frame.
If your vehicle has a trailer hitch, the seven-wire
harness assembly with connector is attached to a
bracket on the hitch platform. In both cases, the
seven-wire harness has a connector and includes a
30-amp feed wire.
4-41