2007 GMC ENVOY automatic transmission

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 transaxle
has been shifted out of the PARK (P) 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 PARK (P).
The vehicle has a light sensor on the top of the
instrument panel. Make sure it is not covered or the
system may come on whenever the ignition is on
and the vehicle is shifted out of the PARK (P)
position.
The system could also turn on the lamps when
driving through a parking garage, heavy overcast
weather or a tunnel. This is normal.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 you start your vehicle in a dark garage, the
automatic headlamp system comes on after the
transmission is shifted out of PARK (P). Once you
leave the garage, it will take 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 179.
181

SERVICE TIRE MONITOR
This message displays if a part on the Tire
Pressure Monitor (TPM) system is not working
properly. If you drive your vehicle while any of the
four sensors are missing or inoperable, the
warning comes on in about 20 minutes. A sensor
would be missing, for example, if you put
different wheels on your vehicle without
transferring the sensors. If the warning comes on
and stays on, there may be a problem with the
TPM. See your dealer.
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 348.
To turn the StabiliTrak
®system back on, press the
StabiliTrak®button again.
227

For more information on the stability messages,
seeDIC Warnings and Messages on page 222.
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.
You may also feel or hear the system 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.
310

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. If you do, you may be causing
damage to the transfer case. This could lead to
costly repairs not covered by your warranty.
Notice:If you allow the wheel(s) of one axle
to spin excessively while the StabiliTrak
®,
ABS and brake warning lights and the
SERVICE STABILITRAK message are
displayed, you could damage the transfer
case. The repairs would not be covered by your
warranty. Reduce engine power and do not
spin the wheel(s) excessively while these lights
and this message 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, you may
notice a reduction in acceleration, or may hear a
noise or vibration. This is normal.If your vehicle is in cruise control when the system
activates, the StabiliTrak
®light will blink, and
the cruise control will automatically disengage.
When road conditions allow, you may re-engage
the cruise control. SeeCruise Control on
page 176.
StabiliTrak
®will turn off automatically if a problem
is detected in the system. The StabiliTrak®
light will come on and SERVICE STABILITRAK
will be displayed on the DIC. For vehicles without a
DIC, the StabiliTrak
®light and the StabiliTrak®
service light will both come on. If the SERVICE
STABILITRAK message (or StabiliTrak®service
light) does not clear itself after restarting the
vehicle, you should see your dealer for service.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 380for more information.
313

Dolly Towing
Front Towing
(Front Wheels Off the Ground)
Two-Wheel-Drive Vehicles
Notice:If you tow a two-wheel-drive vehicle
with the rear wheels on the ground, the
transmission could be damaged. The repairs
would not be covered by your warranty.
Never tow your vehicle with the rear wheels on
the ground.
Four-Wheel-Drive Vehicles
Four-wheel-drive vehicles can be dolly towed with
the rear wheels on the ground.
Use the following procedure to tow your vehicle:
1. Drive the vehicle onto the tow dolly.
2. Shift the automatic transmission to PARK (P).
3. Turn the engine off, but leave the ignition on.
4. Firmly set the parking brake.
5. Securely attach the vehicle being towed to
the dolly.
{CAUTION:
Shifting a four-wheel-drive vehicle’s
transfer case into NEUTRAL can cause
your vehicle to roll even if the transmission
is in PARK (P). You or others could be
injured. Make sure the parking brake is
rmly set before you shift the transfer case
to NEUTRAL.
6. Shift the transfer case to NEUTRAL (N).
SeeFour-Wheel Drive on page 122for
the proper procedure to select the
NEUTRAL (N) position for your vehicle.
7. Release the parking brake only after the
vehicle being towed is rmly attached to
the towing vehicle.
8. Turn the ignition off.
After towing, see “Shifting Out of Neutral”
underFour-Wheel Drive on page 122.
358

Turn Signals When Towing a Trailer
The arrows on your instrument panel will
ash whenever you signal a turn or lane change.
Properly hooked up, the trailer lamps will also
ash, telling other drivers you’re about to
turn, change lanes or stop.
When towing a trailer, the arrows on your
instrument panel will ash for turns even if the
bulbs on the trailer are burned out. Thus, you may
think drivers behind you are seeing your signal
when they are not. It’s important to check
occasionally to be sure the trailer bulbs are
still working.
Driving On Grades
Reduce speed and shift to a lower gearbefore
you start down a long or steep downgrade. If you
don’t shift down, you might have to use your
brakes so much that they would get hot and no
longer work well.
You can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or a lower gear,
under heavy loads or hilly conditions.
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 you turn your engine off immediately
after towing at high altitude on steep uphill grades,
your 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 PARK (P) for a few
minutes before turning the engine off. If you do get
the overheat warning, seeEngine Overheating
on page 408.
372

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal
down while you:
start your 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
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 uid (don’t overll), engine
oil, axle lubricant, belt(s), cooling system and
brake system. Each of these is covered in
this manual, and the Index will help you nd 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.
374

Service........................................................ 380
Accessories and Modications................... 380
California Proposition 65 Warning.............. 381
Doing Your Own Service Work.................. 381
Adding Equipment to the Outside of
Your Vehicle.......................................... 382
Fuel............................................................. 382
Gasoline Octane........................................ 382
Gasoline Specications.............................. 383
California Fuel........................................... 383
Additives................................................... 383
Fuels in Foreign Countries........................ 384
Filling the Tank......................................... 385
Filling a Portable Fuel Container............... 387
Checking Things Under the Hood.............. 388
Hood Release........................................... 388
Engine Compartment Overview.................. 390
Engine Oil................................................. 394
Engine Oil Life System.............................. 398
Engine Air Cleaner/Filter............................ 400
Automatic Transmission Fluid.................... 401
Engine Coolant.......................................... 405Radiator Pressure Cap.............................. 408
Engine Overheating................................... 408
Cooling System......................................... 411
Engine Fan Noise..................................... 416
Power Steering Fluid ................................. 417
Windshield Washer Fluid........................... 418
Brakes...................................................... 419
Battery...................................................... 422
Jump Starting............................................ 423
Rear Axle.................................................... 428
Four-Wheel Drive........................................ 428
Front Axle................................................... 429
Bulb Replacement....................................... 430
Halogen Bulbs........................................... 430
Headlamps................................................ 431
Front Turn Signal, Sidemarker and
Parking Lamps....................................... 432
Taillamps, Turn Signal, and Stoplamps...... 432
Back-Up Lamps......................................... 434
License Plate Lamp................................... 435
Replacement Bulbs................................... 435
Section 5 Service and Appearance Care
377