2021 Chevrolet Silverado 2500HD Owners Manual - Drive Systems

Drive Systems

Four-Wheel Drive

If equipped, four-wheel drive engages the front axle for extra traction.

Read the appropriate section for transfer case operation before using.

Driving on clean, dry pavement in 4 m or 4 n may:

Cause a vibration to be felt in the steering system.

Cause tires to wear faster.

An engagement noise and bump is normal when shifting between 4 n and 4 m or N (Neutral), with the engine running.

Shifting into 4 n will turn Traction Control and StabiliTrak/Electronic Stability Control (ESC) off. See Traction Control/Electronic Stability Control 0 242.

Two-Speed Transfer Case

If equipped, the transfer case controls are used to shift into and out of four-wheel drive.

To shift the transfer case, press the desired button. The graphic in the instrument cluster will flash while a shift is in progress. The graphic displayed will change to indicate the setting requested.

When the shift is complete the graphic will stop flashing. The DIC message turns off once the shift is complete. If the transfer case cannot complete a shift request, it will go back to its last chosen setting.

The settings are:

N (Neutral) : Use only when the vehicle needs to be towed. See Recreational Vehicle Towing 0 370 or

Towing the Vehicle 0 369.

2 m (Two-Wheel Drive High) : Use for driving on most streets and highways. The front axle is not engaged. This setting provides the best fuel economy.

AUTO (Automatic Four-Wheel Drive) : Use when road surface conditions are variable. When driving in AUTO, the front axle is engaged, and the vehicle's power is sent to the front and rear wheels automatically

based on driving conditions. This setting provides slightly lower fuel economy than 2 m.

m (Four-Wheel Drive High) : Use this setting when extra traction is needed, such as when driving on snowy or icy roads, when off-roading, or when plowing snow.

4 n (Four-Wheel Drive Low) : This setting engages the front axle and delivers extra torque. Choose 4 n when driving off-road in deep sand, deep mud, or deep snow, and while climbing or descending steep hills. While driving in 4 n, keep vehicle speed below 72 km/h (45 mph).

Shifting into 4 n will turn Traction Control and StabiliTrak/ESC off. See Traction Control/ Electronic Stability Control 0 242.

Shifts between 2m, 4 m, and AUTO

Any of these shifts can be made at normal driving speed.

The actual 4x4 shift request is only made after the button is released. The 4x4 graphic will remain flashing until the shift request has completed. A DIC message displays to indicate that the 4x4 transfer case has been requested to shift to the new desired state.

Once the 4x4 shift has completed, the DIC message disappears, the 4x4 graphic stops flashing, and the current setting is indicated.