2009 GMC ENVOY automatic transmission

Headlamps on Reminder
A reminder tone sounds when the headlamps or
parking lamps are manually turned on, if the driver’s
door is open and the ignition is in LOCK/OFF or
ACC/ACCESSORY. To turn the tone off, turn the knob
all the way counterclockwise.
In the automatic mode, the headlamps turn off once the
ignition key is in LOCK/OFF.
Daytime Running Lamps (DRL)
Daytime Running Lamps (DRL) can make it easier for
others to see the front of your vehicle during the day.
Fully functional DRL are required on all vehicles
rst sold in Canada.
The DRL system makes the headlamps come on at
reduced brightness when the following conditions
are met:
The ignition is on.
The exterior lamps knob is in automatic
headlamp mode.
The light sensor detects daytime light.
The transmission is not in P (Park).When the DRL are on, only the headlamps will be on.
The taillamps, sidemarker, instrument panel lights
and other lamps will not be on.
When it begins to get dark, the headlamps automatically
switch from DRL to the regular headlamps.
Automatic Headlamp System
When it is dark enough outside, the Automatic
Headlamp System turns on the headlamps when
the vehicle is started and after the transmission
has been shifted out of the P (Park) position.
The headlamps, taillamps, sidemarker, and parking
lamps will come on. The instrument panel lights
and radio lights will also turn on at normal brightness.
Once on, the system remains on during these conditions
even if the vehicle is shifted back into P (Park).
The vehicle has a light sensor on the top of the
instrument panel. Do not cover the sensor or the system
may come on whenever the ignition is on and the
vehicle is shifted out of the P (Park) position.
The system could also turn on the lamps when driving
through a parking garage, heavy overcast weather
or a tunnel. This is normal.
3-14

There is a delay in the transition between the daytime
and nighttime operation of the Daytime Running
Lamps (DRL) and the automatic headlamp systems,
so that driving under bridges or bright overhead street
lights does not affect the system. The DRL and
automatic headlamp system are only affected when the
light sensor sees a change in lighting lasting longer
than the delay.
If the vehicle is started in a dark garage, the automatic
headlamp system comes on after the transmission
is shifted out of P (Park). Once the vehicle leaves the
garage, it takes about one minute for the automatic
headlamp system to change to DRL if it is light outside.
During that delay, the instrument panel cluster might
not be as bright as usual. Make sure the instrument
panel brightness control is in the full bright position.
If the vehicle is running and the automatic headlamp
system is already on, it can be turned off by turning and
releasing the headlamp control at the off position.
The automatic headlamp system stays off until you turn
and release the headlamp control at the off position
again. SeeHeadlamps on page 3-13.Fog Lamps
The fog lamp button is located on the instrument panel
to the right of the exterior lamps knob. Use the fog
lamps for better vision in foggy or misty conditions.
The ignition must be in ON/RUN for the fog lamps
to work.
#:Press to turn the fog lamps on or off. An indicator
light turns on near the button while the fog lamps
are on. Fog lamps turn off whenever the high-beam
headlamps are on.
Some localities have laws that require the headlamps
to be on along with the fog lamps.
3-15

SERVICE TIRE MONITOR
On vehicles with the Tire Pressure Monitor System
(TPMS), this message displays if a part on the TPMS is
not working properly. The tire pressure light also ashes
and then remains on during the same ignition cycle. See
Tire Pressure Light on page 3-38. Several conditions may
cause this message to appear. SeeTire Pressure Monitor
Operation on page 5-64for more information. If the
warning comes on and stays on, there may be a problem
with the TPMS. See your dealer/retailer.
STABILITRAK ACTIVE
This message displays anytime the StabiliTrak system
activates to maintain vehicle stability. Any combination
of engine speed management, brake traction control,
and stability control displays this message.
STABILITRAK NOT READY
This message may display if driving conditions delay
StabiliTrak system initialization. This is normal. Once the
system initializes, this message will no longer be
displayed on the DIC.
STABILITRAK OFF
This message displays when you press the StabiliTrak
button for more than ve seconds or when stability
control has been automatically disabled. The StabiliTrak
button is located on the transmission shift handle.
To limit wheel spin and realize the full benets of the
stability enhancement system, you should normally
leave StabiliTrak on. However, you should turn
StabiliTrak off if your vehicle gets stuck in sand, mud,
ice, or snow and you want to rock your vehicle to
attempt to free it, or if you are driving in extreme off-road
conditions and require more wheel spin. SeeIf Your
Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 4-30. To turn the StabiliTrak system back on,
press the StabiliTrak button again.
There are several conditions that can cause this
message to appear.
The message may display if the brake system
warning light is on. SeeBrake System Warning
Light on page 3-35.
The message displays if the vehicle is shifted
into 4LO.
The message turns off as soon as the conditions that
caused the message to be displayed are no longer
present.
3-55

When the StabiliTrak
system is both on and
actively controlling the
stability of the vehicle, the
StabiliTrak light will blink for
the duration of the event.
The system may be heard or felt while it is working.
This is normal.
The StabiliTrak disable
button is located on the
transmission shift handle.
The StabiliTrak system is automatically disabled in
4LO mode and cannot be turned on until the vehicle is
switched to 2HI, 4HI, or 4AWD.
The StabiliTrak system has three modes of operation:
STABILITRAK ON, TRACTION CONTROL OFF, and
STABILITRAK OFF.
STABILITRAK ON — The vehicle will default to
STABILITRAK ON every time the driver starts the
vehicle. The StabiliTrak light will be off and no DIC
messages will be displayed.TRACTION CONTROL OFF — The driver can modify
the engine speed management system by momentarily
pressing the StabiliTrak button on the transmission shift
handle. The StabiliTrak light will come on and TRACTION
CONTROL OFF will be displayed. For vehicles without
a DIC, the StabiliTrak indicator light will come on.
Momentarily pressing the StabiliTrak button again will
return the system to the STABILITRAK ON mode.
STABILITRAK OFF — The driver can turn off
StabiliTrak by pressing the StabiliTrak button for more
than ve seconds. The StabiliTrak light will come on
and STABILITRAK OFF will be displayed. For vehicles
without a DIC, the StabiliTrak indicator light will
come on. Momentarily pressing the StabiliTrak button
again will return the system to the STABILITRAK
ON mode. See StabiliTrak Off below for more
information.
Traction Control Off
In this mode, stability control and brake-traction control
are functional. Engine speed management will be
modied and the driven wheels can spin more freely.
This can cause the brake-traction control to activate
more frequently. If the controller detects excessive wheel
spin in this mode, the StabiliTrak indicator light may
blink and the STABILITRAK ACTIVE message may be
displayed to warn the driver that damage may occur
to the transfer case.
4-7

Vehicles with a DIC Vehicles without a DIC Event
Blinking StabiliTrak Active Blinking OffStabiliTrak system activates using
engine speed management, brake
traction control, and/or stability
control.
SolidService
StabiliTrakSolid SolidStabiliTrak system is disabled due to
a system fault.
SolidStabiliTrak Not
ReadySolid OffStabiliTrak system is disabled due to
a failure to initialize.
Notice:If the StabiliTrak
®light comes on due to
heavy braking and/or because the traction control
system has been continuously active, do not allow
the wheel(s) of one axle to spin excessively. This
could lead to damage to the transfer case and costly
repairs not covered by the vehicle warranty.
Notice:If the wheel(s) of one axle is allowed to spin
excessively while the StabiliTrak, ABS and brake
warning lights and any relevant DIC messages are
displayed, the transfer case could be damaged. The
repairs would not be covered by the vehicle warranty.
Reduce engine power and do not spin the wheel(s)
excessively while these lights and messages are
displayed.StabiliTrak may activate on dry or rough roads or under
conditions such as heavy acceleration while turning
or abrupt upshifts/downshifts of the transmission. When
this happens, a reduction in acceleration may be noticed,
or a noise or vibration may be heard. This is normal.
If cruise control is being used when the system activates,
the StabiliTrak light will ash and cruise control will
automatically disengage. Cruise control may be
reengaged when road conditions allow. SeeCruise
Control on page 3-10.
4-9

Pulling A Trailer
Here are some important points:
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
the rig will be legal, not only where you live but
also where you will be driving. A good source for
this information can be state or provincial police.
Consider using a sway control. See “Hitches” later
in this section.
Do not tow a trailer at all during the rst 500 miles
(800 km) the new vehicle is driven. The engine,
axle or other parts could be damaged.
Then, during the rst 500 miles (800 km) that a
trailer is towed, do not drive over 50 mph (80 km/h)
and do not make starts at full throttle. This helps
the engine and other parts of the vehicle wear in at
the heavier loads.
Vehicles with an automatic transmissions 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.Three important considerations have to do with weight:
The weight of the trailer
The weight of the trailer tongue
The weight on the vehicle’s tires
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how the rig is used. For example, speed,
altitude, road grades, outside temperature and how much
the vehicle is used to pull a trailer are all important. It can
depend on any special equipment on the vehicle, and the
amount of tongue weight the vehicle can carry. See
“Weight of the Trailer Tongue” later in this section for
more information.
Maximum trailer weight is calculated assuming only the
driver is in the tow vehicle and it has all the required
trailering equipment. The weight of additional optional
equipment, passengers and cargo in the tow vehicle
must be subtracted from the maximum trailer weight.
4-47

Leaving After Parking on a Hill
1. Apply and hold the brake pedal while you:
start the engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
The vehicle needs service more often when pulling a
trailer. See this manual’s Maintenance Schedule
or Index for more information. Things that are especially
important in trailer operation are automatic transmission
uid, engine oil, axle lubricant, belts, cooling system
and brake system. It is a good idea to inspect
these before and during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The vehicle may have a seven-wire trailer towing
harness. This harness may have a seven-pin universal
heavy-duty trailer connector (if equipped with the
trailering package) that is attached to a bracket on
the hitch platform or included with the four-pin trailer
towing harness. If the vehicle is not equipped with the
heavy-duty trailer connector, one may be purchased from
your dealer/retailer.
4-56

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of the
Vehicle......................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-21
Cooling System............................................5-24
Engine Coolant.............................................5-25
Engine Overheating.......................................5-30
Engine Fan Noise.........................................5-32Power Steering Fluid.....................................5-33
Windshield Washer Fluid................................5-34
Brakes........................................................5-35
Battery........................................................5-38
Jump Starting...............................................5-39
Rear Axle.......................................................5-43
Four-Wheel Drive............................................5-44
Front Axle......................................................5-44
Headlamp Aiming
...........................................5-45
Bulb Replacement..........................................5-46
Halogen Bulbs..............................................5-46
Headlamps..................................................5-46
Front Turn Signal, Sidemarker and
Parking Lamps..........................................5-47
Taillamps, Turn Signal, and Stoplamps............5-47
Back-Up Lamps............................................5-48
License Plate Lamp......................................5-49
Replacement Bulbs.......................................5-49
Windshield Wiper Blade Replacement..............5-50
Tires..............................................................5-53
Tire Sidewall Labeling...................................5-54
Tire Terminology and Denitions.....................5-57
Ination - Tire Pressure.................................5-60
High-Speed Operation...................................5-62
Tire Pressure Monitor System.........................5-63
Section 5 Service and Appearance Care
5-1