Chevrolet Silverado 2500 HD 2023 Owner's Manual page 231

230 Driving and Operating
This number is the highest gear that the
transmission will allow while operating in
L (Manual Mode). All gears below that
number are available. As driving conditions
change, the transmission can automatically
shift to lower gears. For example, when L5 is
selected, 1 (First) through 5 (Fifth) gears are
automatically shifted by the transmission,
but 6 (Sixth) cannot be used until the plus/
minus button on the shift lever is used to
change to the range.
In vehicles with gasoline engines, when the
shift lever is moved from D (Drive) to
L (Manual Mode), a downshift may occur.
The gear that the transmission is operating
in when the shift lever is moved from D
(Drive) to L (Manual Mode) determines if a
downshift occurs. See the following charts.
6-Speed Automatic Transmission
Gear before shifting from D (Drive) to
L (Manual Mode)
Range after shifting from D (Drive) to
L (Manual Mode)
6th 5th 4th 3rd
L4 L4 L3 L2
2nd 1st
L2 L1