Four-Wheel Drive; Automatic Transfer Case - GMC 2003 Envoy XL Owner's Manual

Four-wheel Drive
If your vehicle has four-wheel drive, you can send your
engine's driving power to all four wheels for extra
traction. To get the most satisfaction out of four-wheel
drive, you must be familiar with its operation. Read
the part that follows before using four-wheel drive.
You should use two-wheel drive high (2HI) for most
normal driving conditions.
Notice:
Driving in the 4-WHEEL HIGH (4HI) or
4-WHEEL LOW (4LO) positions for a
long
time on
dry or wet pavement could shorten the life of
your vehicle's drivetrain.
Automatic Transfer Case
If your vehicle is equipped
with the automatic transfer
case, the transfer case
knob is located to the right
of the steering wheel on the
instrument panel. Use this
knob to shift into and out of
four-wheel drive.
2HI (Two-Wheel High): This setting is for driving in
most street and highway situations. Your front axle is not
engaged in two-wheel drive.
It
also provides the best
fuel economy.
A4WD (Automatic Four-wheel Drive): This setting is
ideal for use when road conditions are variable.
When driving your vehicle in A4WD, the front axle is
engaged, but the vehicle's power is sent to the
rear wheels. When the vehicle senses a
loss
of traction.
the system will automatically engage four-wheel
drive. Driving in this mode results in slightly lower fuel
economy than 2HI.
4HI (Four-wheel High): Use 4HI when you need extra
traction, such as on snowy or icy roads or in most
off-road situations. This setting also engages your front
axle to help drive your vehicle.
4LO (Four-wheel Low): This setting also engages
your front axle and delivers extra torque. You may never
need 4LO.
It
sends maximum power to all four wheels.
You might choose 4LO if you are driving off-road in
deep sand, deep mud, and climbing or descending
steep hills.
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