Hummer 2009 H2 - Manual (Page 123)

Cruise Grade Braking
Cruise Grade Braking operates while Cruise Control
is engaged in Tow/Haul mode to assist in maintaining
vehicle speed under loaded vehicle conditions. Cruise
Grade Braking assists when driving on a downhill grade.
It maintains vehicle speed by automatically implementing
a shift schedule that uses the engine and the
transmission to slow the vehicle. If vehicle speed is
above the desired speed the transmission will downshift
to slow the vehicle. If vehicle speed is near or below
desired speed the trans will upshift, allowing vehicle
speed to increase.
While in the Range Select Mode (RSM) mode, cruise
grade braking is not available.
See Automatic Transmission Operation on page 2-32.
Full-Time Four-Wheel Drive
The Full-Time Four-Wheel Drive transfer case is
designed to constantly send the engine’s driving power
to all four wheels for extra traction. To get the most
out of Full-Time Four-Wheel Drive, you must be familiar
with its operation.
Notice: Driving on pavement in Four-Wheel
High Lock or Four Wheel Low Lock for extended
periods may cause premature wear on the vehicle
powertrain and tires. Do not drive in Four-Wheel
High Lock or Four-Wheel Low Lock on pavement
for extended periods.
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