GMC SIERRA 2020 Owner's Manual page 227

226 Driving and Operating
10-Speed Automatic Transmission
Gear before shifting from D (Drive) to
L (Manual Mode)
Range after shifting from D (Drive) to
L (Manual Mode) - Tow/Haul not engaged
Range after shifting from D (Drive) to
L (Manual Mode) - Tow/Haul engaged
Grade Braking is not available when
Range Selection Mode is active.
See Tow/Haul Mode 0 227.
While using Range Selection Mode,
cruise control and the Tow/Haul
Mode can be used.
If the vehicle has an exhaust brake,
it can also be used, but will not
automatically downshift the
transmission. See Exhaust Brake
in the Duramax diesel supplement.
10th 9th 8th
L7 L7 L7
L7 L7 L6
Caution
Spinning the tires or holding the
vehicle in one place on a hill
using only the accelerator pedal
may damage the transmission.
The repair will not be covered by
the vehicle warranty. If the vehicle
is stuck, do not spin the tires.
When stopping on a hill, use the
brakes to hold the vehicle in
place.
7th 6th 5th 4th
L6 L5 L4 L3
L5 L4 L3 L3
Low Traction Mode
If equipped, Low Traction Mode
assists in vehicle acceleration when
road conditions are slippery, such
as with ice or snow. While the
vehicle is at a stop, select L2 using
Range Selection Mode. This will
limit torque to the wheels and help
prevent the tires from spinning.
3rd 2nd 1st
L3 L2 L1
L3 L2 L1