Hummer 2004 H2 - Manual (Page 106)

I
(4LO Lock): This mode delivers extra torque to all
four wheels and is used for extreme off-road conditions.
You might choose 4LO Lock if you are driving off-road,
deep sand, mud, or snow and climbing or descending
steep hills.
When in this mode you can also choose to lock the rear
axle for additional traction in extreme off-road situations.
See Locking Rear Axle on page 4-11.
Notice: Operating your vehicle in 4LO Lock above
50 mph (80 km/h) for any extended period of time
could cause damage to the transfer case. Do
not operate your vehicle in 4LO Lock above 50 mph
(80 km/h) for extended periods.
{ CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. See Parking Brake on
page 2-29.
N (NEUTRAL): Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-65 or Towing
Your Vehicle on page 4-65 for more information.
Indicator lights in the buttons show which mode you are
in. The indicator lights will come on briefly when you
turn on the ignition and one will stay on. If the lights do
not come on, you should take your vehicle to your
dealer for service. An indicator light will flash while
shifting the transfer case. It will remain illuminated when
the shift is complete. If for some reason the transfer
case cannot make a requested shift, it will return to the
last chosen setting.
If the SERVICE 4WD message stays on, you should
take your vehicle to your dealer for service. See “Service
4WD message” under Driver Information Center (DIC)
on page 3-44.
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