GMC Sierra Owners Manual

Four-Wheel Drive
Driving and Operating / Drive Systems / Four-Wheel Drive

If the vehicle has Four-Wheel Drive, you can send the engine's driving power to all four wheels for extra traction. To get the most satisfaction out of Four-Wheel Drive, you must be familiar with its operation. Read the following before using Four-Wheel Drive. See the appropriate text for the transfer case in the vehicle.

Notice: Driving on clean, dry pavement in Four-Wheel Drive High or Four-Wheel Drive Low for an extended period of time may cause premature wear on the vehicle's powertrain. Do not drive on clean, dry pavement in Four-Wheel Drive High or Four-Wheel Drive Low for extended periods of time.

While driving on clean dry pavement and during tight turns, you may experience vibration in the steering system.

9-44 Driving and Operating If the vehicle has StabiliTrak, shifting into Four-Wheel Drive Low will turn Traction Control and StabiliTrak off. See StabiliTrak System on page 9‑59.

Front Axle

The front axle engages and disengages automatically when you shift the transfer case. Some delay for the axle to engage or disengage is normal.

Manual Transfer Case

GMS Sierra: Four-Wheel Drive. The transfer case shift lever is on the floor to the right of the driver.

The transfer case shift lever is on the floor to the right of the driver.

Use this lever to shift into and out of Four-Wheel Drive.

GMS Sierra: Four-Wheel Drive. A Four-Wheel Drive indicator light comes on when you shift into four-wheel drive and the front axle engages. See Four-Wheel-Drive Light on page 5‑29.

A Four-Wheel Drive indicator light comes on when you shift into four-wheel drive and the front axle engages. See Four-Wheel-Drive Light on page 5‑29.

Some delay between shifting and when the indicator light comes on is normal.

Recommended Transfer Case Settings

GMS Sierra: Four-Wheel Drive. Notice: Driving on clean, dry pavement in four-wheel drive for an extended period of time can cause premature wear on the vehicle's powertrain. Do not drive on clean, dry pavement in Four-Wheel Drive for extended periods of time.

Notice: Driving on clean, dry pavement in four-wheel drive for an extended period of time can cause premature wear on the vehicle's powertrain. Do not drive on clean, dry pavement in Four-Wheel Drive for extended periods of time.

4 GMS Sierra: Four-Wheel Drive. It sends maximum power to all four wheels. You might choose Four-Wheel Drive Low if you are driving off-road in deep sand, deep mud, deep snow, and while climbing or descending steep hills. (Four-Wheel Drive Low): This setting also engages the front axle and delivers extra torque. You may never need Four-Wheel Drive Low.

It sends maximum power to all four wheels. You might choose Four-Wheel Drive Low if you are driving off-road in deep sand, deep mud, deep snow, and while climbing or descending steep hills.

If the vehicle has StabiliTrak, shifting into Four-Wheel Drive Low will turn Traction Control and StabiliTrak off. See StabiliTrak System on page 9‑59.

GMS Sierra: Four-Wheel Drive. A parking brake symbol is located next to the N (Neutral) symbol as a reminder to set the parking brake before shifting the transfer case into N (Neutral).

A parking brake symbol is located next to the N (Neutral) symbol as a reminder to set the parking brake before shifting the transfer case into N (Neutral).

WARNING
Shifting the transfer case to N (Neutral) can cause the vehicle to roll even if the transmission is in P (Park). You or someone else could be seriously injured. Be sure to set the parking brake before placing the transfer case in N (Neutral). See Parking Brake on page 9‑58.

N (Neutral): Shift to this setting only when the vehicle needs to be towed. See Recreational Vehicle Towing on page 10‑96 or Towing the Vehicle on page 10‑96.

2 GMS Sierra: Four-Wheel Drive. The front axle is not engaged in two-wheel drive. This setting also provides the best fuel economy. (Two-Wheel Drive High): This setting is used for driving in most street and highway situations.

The front axle is not engaged in two-wheel drive. This setting also provides the best fuel economy.

4 GMS Sierra: Four-Wheel Drive. This setting also engages the front axle to help drive your vehicle. This is the best setting to use when plowing snow. (Four-Wheel Drive High): Use this setting when you need extra traction, such as on snowy or icy roads or in most off-road situations.

This setting also engages the front axle to help drive your vehicle. This is the best setting to use when plowing snow.

You can shift from Two-Wheel Drive High to Four-Wheel Drive High or Four-Wheel Drive High to Two-Wheel Drive High while the vehicle is moving. In extremely cold weather, it may be necessary to stop or slow the vehicle to shift into Four-Wheel Drive High.

When Using the Manual Transfer Case

Shifts into or out of Four-Wheel Drive Low or N (Neutral) should be made using quick motions to avoid excessive gear grinding.

Shifting slowly may make it more difficult to shift.

You may notice that it is harder to shift when the vehicle is cold.

After the vehicle warms up the shifting will return to normal.

While in Four-Wheel High or Four-Wheel Drive Low you may experience reduced fuel economy.

Avoid driving in Four-Wheel Drive on clean, dry pavement.

It may cause your tires to wear faster, make the transfer case harder to shift, and run noisier.

If the transfer case shifter is in the N (Neutral) position and you have difficulty reaching the selected transfer case mode, with the engine running, shift the transmission momentarily to D (Drive) and then back to N (Neutral). This will realign the gear teeth in the transfer case and allow you to complete the shift.

Shifting from Two-Wheel Drive High to Four-Wheel Drive High

Shifts between Two-Wheel Drive High and Four-Wheel Drive High can be made at any vehicle speed.

Shift the transfer case lever in one continuous motion into either the Four-Wheel Drive High or Two-Wheel Drive High position.

Shifting from Two-Wheel Drive High to Four-Wheel Drive High while the vehicle is in motion may require that moderate force be applied to the shift lever for a few seconds before Four-Wheel Drive High can be engaged, especially in cold weather.

In extremely cold weather, it may be necessary to slow or stop the vehicle to shift into Four-Wheel Drive High.

While in Four-Wheel Drive High, the vehicle can be driven at any posted legal speed limit.

Shifting In or Out of Four-Wheel Drive Low

Notice: Shifting the transfer case into Four-Wheel-Drive Low while moving at speeds faster than 5 km/h (3 mph) may cause premature wear to the transfer case, and may cause the gears to grind. To avoid causing premature wear, and grinding the gears, do not shift the transfer case into Four-Wheel-Drive Low while the vehicle is moving faster than 5 km/h (3 mph).

Shifting into Four-Wheel Drive Low should be done, if possible, with the vehicle at a slight roll, 5 km/h (3 mph) or less.

Shift the transmission into N (Neutral).

WARNING
Shifting the transfer case to N (Neutral) can cause the vehicle to roll even if the transmission is in P (Park). You or someone else could be seriously injured. Be sure to set the parking brake before placing the transfer case in N (Neutral). See Parking Brake on page 9‑58.

Shifting into Four-Wheel Drive Low with the vehicle at a stop may be more difficult. You may be unable to complete the shift to Four-Wheel Drive Low, and the transfer case will end up in N (Neutral). This is normal, and is a function of the gear teeth aligning in the transfer case.

When this happens, make sure the engine is on, shift the transmission momentarily to D (Drive) and back to N (Neutral), and then complete the transfer case shift.

Shift the transfer case shift lever in one continuous motion into the Four-Wheel Drive Low position.

When in Four-Wheel Drive Low do not drive faster than 72 km/h (45 mph). This will reduce wear and extend the life of your transfer case.

Shifting In or Out of Neutral

1. With the vehicle running and the engine at an idle, set the parking brake.

2. Place the transmission into N (Neutral).

Shift the transfer case in one continuous motion into or out of the N (Neutral) position.

Electronic Transfer Case

GMS Sierra: Four-Wheel Drive. The transfer case knob is located next to the steering column.

The transfer case knob is located next to the steering column.

Use the dial to shift into and out of four-wheel drive.

Recommended Transfer Case Settings

GMS Sierra: Four-Wheel Drive. You can choose among four driving settings:

You can choose among four driving settings:

Indicator lights in the dial show which setting 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 the vehicle to your dealer for service.

An indicator light flashes while shifting the transfer case and remains 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.

2 GMS Sierra: Four-Wheel Drive. 4  (Four-Wheel Drive High): Use the Four-Wheel Drive High position when extra traction is needed, such as on snowy or icy roads or in most off-road situations. This setting also engages the front axle to help drive the vehicle. This is the best setting to use when plowing snow. (Two-Wheel Drive High): This setting is used for driving in most street and highway situations. The front axle is not engaged in Two-Wheel Drive. This setting also provides the best fuel economy.

4 GMS Sierra: Four-Wheel Drive. 4  (Four-Wheel Drive Low): This setting also engages the front axle and delivers extra torque. You may never need this setting. It sends maximum power to all four wheels. (Four-Wheel Drive High): Use the Four-Wheel Drive High position when extra traction is needed, such as on snowy or icy roads or in most off-road situations. This setting also engages the front axle to help drive the vehicle. This is the best setting to use when plowing snow.

4 GMS Sierra: Four-Wheel Drive. You might choose Four-Wheel Drive Low while driving off-road in deep sand, deep mud, deep snow, and while climbing or descending steep hills. (Four-Wheel Drive Low): This setting also engages the front axle and delivers extra torque. You may never need this setting. It sends maximum power to all four wheels.

You might choose Four-Wheel Drive Low while driving off-road in deep sand, deep mud, deep snow, and while climbing or descending steep hills.

If the vehicle has StabiliTrak, shifting into Four-Wheel Drive Low will turn Traction Control and StabiliTrak off. See StabiliTrak System on page 9‑59.

WARNING
Shifting the transfer case to N (Neutral) can cause the vehicle to roll even if the transmission is in P (Park). You or someone else could be seriously injured. Be sure to set the parking brake before placing the transfer case in N (Neutral). See Parking Brake on page 9‑58.

N (Neutral): Shift the vehicle's transfer case to N (Neutral) only when towing the vehicle. See Recreational Vehicle Towing on page 10‑96 or Towing the Vehicle on page 10‑96 for more information.

If the SERVICE 4 WHEEL DRIVE message stays on, you should take the vehicle to your dealer for service. See SERVICE 4 WHEEL DRIVE message under Transmission Messages on page 5‑50.

Shifting Into Two-Wheel Drive High

Turn the knob to the Two-Wheel Drive High position. This can be done at any speed, except when shifting from Four-Wheel Drive Low.

See Shifting Out of Four-Wheel Drive Low for more information.

Shifting Into Four-Wheel Drive Low

When Four-Wheel Drive Low is engaged, vehicle speed should be kept below 72 km/h (45 mph).

Extended high-speed operation in Four-Wheel Drive Low may damage or shorten the life of the drivetrain.

To shift to the Four-Wheel Drive Low position, the ignition must be in ON/RUN and the vehicle must be stopped or moving less than 5 km/h (3 mph) with the transmission in N (Neutral). The preferred method for shifting into Four-Wheel Drive Low is to have the vehicle moving 1.6 to 3.2 km/h (1 to 2 mph). Turn the knob to the Four-Wheel Drive Low position. You must wait for the Four-Wheel Drive Low indicator light to stop flashing and remain on before shifting the transmission in gear.

Notice: Shifting the transmission into gear before the requested mode indicator light has stopped flashing could damage the transfer case. To help avoid damaging the vehicle, always wait for the mode indicator lights to stop flashing before shifting the transmission into gear.

It is typical for the vehicle to exhibit significant engagement noise and bump when shifting between Four-Wheel Drive Low and Four-Wheel Drive High ranges or from transfer case N (Neutral) with the engine running.

If the knob is turned to the Four-Wheel Drive Low position when the vehicle is in gear and/or moving more than 5 km/h (3 mph), the Four-Wheel Drive Low indicator light will flash for 30 seconds and not complete the shift. After 30 seconds the transfer case will shift to Four-Wheel Drive High mode.

Shifting Out of Four-Wheel Drive Low

To shift from Four-Wheel Drive Low to Four-Wheel Drive High, or Two-Wheel Drive High, the vehicle must be stopped or moving less than 5 km/h (3 mph) with the transmission in N (Neutral) and the ignition in ON/RUN. The preferred method for shifting out of Four-Wheel Drive Low is to have the vehicle moving 1.6 to 3.2 km/h (1 to 2 mph). Turn the knob to the Four-Wheel Drive High or Two-Wheel Drive High position. You must wait for the Four-Wheel Drive High or Two-Wheel Drive High indicator light to stop flashing and remain on before shifting the transmission into gear.

Notice: Shifting the transmission into gear before the requested mode indicator light has stopped flashing could damage the transfer case. To help avoid damaging the vehicle, always wait for the mode indicator lights to stop flashing before shifting the transmission into gear.

It is typical for the vehicle to exhibit significant engagement noise and bump when shifting between Four-Wheel Drive Low and Four-Wheel Drive High ranges or from transfer case N (Neutral) with the engine running.

If the knob is turned to the Four-Wheel Drive High, or Two-Wheel Drive High switch position when the vehicle is in gear and/or moving more than 5 km/h (3 mph), the Four-Wheel Drive High, AUTO, or Two-Wheel Drive High indicator light will flash for 30 seconds but will not complete the shift.

Shifting into Neutral

To shift the transfer case to N (Neutral) do the following:

1. Make sure the vehicle is parked so that it will not roll.

2. Set the parking brake and press and hold the regular brake pedal. See Parking Brake on page 9‑58 for more information.

3. Start the vehicle or turn the ignition to ON/RUN.

4. Shift the transmission to N (Neutral).

5. Shift the transfer case to Two-Wheel Drive High.

6. Turn the transfer case dial clockwise to N (Neutral) until it stops and hold it there until the Neutral light starts blinking. This will take at least 10 seconds.

Then slowly release the dial to the four low position. The N (Neutral) light will come on when the transfer case shift to N (Neutral) is complete.

7. If the engine is running, verify that the transfer case is in N (Neutral) by shifting the transmission to R (Reverse) for one second, then shift the transmission to D (Drive) for one second.

8. Turn the ignition to ACC/ ACCESSORY, which will turn the engine off.

9. Place the transmission shift lever in P (Park).

10. Release the parking brake prior to moving the vehicle.

11. Turn the ignition to LOCK/OFF.

Shifting Out of Neutral

To shift the transfer case out of N (Neutral) do the following:

1. Set the parking brake and apply the regular brake pedal.

2. Turn the ignition to ON/RUN with the engine off, and shift the transmission to N (Neutral).

3. Turn the transfer case dial to Two-Wheel Drive High.

After the transfer case has shifted out of N (Neutral), the N (Neutral) light will go out.

4. Release the parking brake prior to moving the vehicle.

Notice: Shifting the transmission into gear before the requested mode indicator light has stopped flashing could damage the transfer case. To help avoid damaging the vehicle, always wait for the mode indicator lights to stop flashing before shifting the transmission into gear.

5. Start the engine and shift the transmission to the desired position.

Excessively shifting the transfer case into or out of the different modes may cause the transfer case to enter the shift protection mode.

This will protect the transfer case from possible damage and will only allow the transfer case to respond to one shift per 10 seconds. The transfer case may stay in this mode for up to three minutes.

Automatic Transfer Case

GMS Sierra: Four-Wheel Drive. The transfer case knob is located next to the steering column.

The transfer case knob is located next to the steering column.

Use the dial to shift into and out of Four-Wheel Drive.

You can choose among five driving settings:

Indicator lights in the dial show which setting 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 the 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.

2 GMS Sierra: Four-Wheel Drive. AUTO (Automatic Four-Wheel Drive): This setting is ideal for use when road surface traction conditions are variable. When driving the vehicle in AUTO, the front axle is engaged, but the vehicle's power is sent only to the front and rear wheels automatically based on driving conditions. Driving in this mode results in slightly lower fuel economy than Two-Wheel Drive High. (Two-Wheel Drive High): This setting is used for driving in most street and highway situations. The front axle is not engaged in Two-Wheel Drive. This setting also provides the best fuel economy.

AUTO (Automatic Four-Wheel Drive): This setting is ideal for use when road surface traction conditions are variable. When driving the vehicle in AUTO, the front axle is engaged, but the vehicle's power is sent only to the front and rear wheels automatically based on driving conditions. Driving in this mode results in slightly lower fuel economy than Two-Wheel Drive High.

4 GMS Sierra: Four-Wheel Drive. 4  (Four-Wheel Drive Low): This setting also engages the front axle and delivers extra torque. You may never need this setting. It sends maximum power to all four wheels. (Four-Wheel Drive High): Use the Four-Wheel Drive High position when extra traction is needed, such as on snowy or icy roads or in most off-road situations. This setting also engages the front axle to help drive the vehicle. This is the best setting to use when plowing snow.

4 GMS Sierra: Four-Wheel Drive. You might choose Four-Wheel Drive Low if you are driving off-road in deep sand, deep mud, deep snow, and while climbing or descending steep hills. (Four-Wheel Drive Low): This setting also engages the front axle and delivers extra torque. You may never need this setting. It sends maximum power to all four wheels.

You might choose Four-Wheel Drive Low if you are driving off-road in deep sand, deep mud, deep snow, and while climbing or descending steep hills.

If the vehicle has StabiliTrak, shifting into Four-Wheel Drive Low will turn Traction Control and StabiliTrak off. See StabiliTrak System on page 9‑59.

WARNING
Shifting the transfer case to N (Neutral) can cause the vehicle to roll even if the transmission is in P (Park). You or someone else could be seriously injured. Be sure to set the parking brake before placing the transfer case in N (Neutral). See Parking Brake on page 9‑58.

N (Neutral): Shift the vehicle's transfer case to N (Neutral) only when towing the vehicle. See Recreational Vehicle Towing on page 10‑96 or Towing the Vehicle on page 10‑96 for more information.

If the SERVICE 4 WHEEL DRIVE message stays on, you should take the vehicle to your dealer for service. See SERVICE 4 WHEEL DRIVE message under Transmission Messages on page 5‑50.

Shifting Into Four-Wheel Drive High or AUTO (Automatic Four-Wheel Drive)

Turn the knob to the Four-Wheel Drive High or AUTO position. This can be done at any speed, except when shifting from Four-Wheel Drive Low. The indicator light will flash while shifting. It will remain on when the shift is completed.

Shifting Into Two-Wheel Drive High

Turn the knob to the Two-Wheel Drive High position. This can be done at any speed, except when shifting from Four-Wheel Drive Low.

The indicator light will flash while shifting. It will remain on when the shift is completed.

Shifting Into Four-Wheel Drive Low

When Four-Wheel Drive Low is engaged, vehicle speed should be kept below 72 km/h (45 mph).

Extended high-speed operation in Four-Wheel Drive Low may damage or shorten the life of the drivetrain.

To shift to the Four-Wheel Drive Low position, the ignition must be in ON/RUN and the vehicle must be stopped or moving less than 5 km/h (3 mph) with the transmission in N (Neutral). The preferred method for shifting into Four-Wheel Drive Low is to have the vehicle moving 1.6 to 3.2 km/h (1 to 2 mph). Turn the knob to the Four-Wheel Drive Low position. You must wait for the Four-Wheel Drive Low indicator light to stop flashing and remain on before shifting the transmission into gear.

Notice: Shifting the transmission into gear before the requested mode indicator light has stopped flashing could damage the transfer case. To help avoid damaging the vehicle, always wait for the mode indicator lights to stop flashing before shifting the transmission into gear.

It is typical for the vehicle to exhibit significant engagement noise and bump when shifting between Four-Wheel Drive Low and Four-Wheel Drive High ranges or from N (Neutral) with the engine running.

If the knob is turned to the Four-Wheel Drive Low position when the vehicle is in gear and/or moving more than 5 km/h (3 mph), the Four-Wheel Drive Low indicator light will flash for 30 seconds and not complete the shift. After 30 seconds the transfer case will shift to Four-Wheel Drive High mode.

Shifting Out of Four-Wheel Drive Low

To shift from Four-Wheel Drive Low to Four-Wheel Drive High, AUTO or Two-Wheel Drive High, the vehicle must be stopped or moving less than 5 km/h (3 mph) with the transmission in N (Neutral) and the ignition in ON/RUN. The preferred method for shifting out of Four-Wheel Drive Low is to have the vehicle moving 1.6 to 3.2 km/h (1 to 2 mph). Turn the knob to the Four-Wheel Drive High, AUTO or Two-Wheel Drive High position. You must wait for the Four-Wheel Drive High, AUTO or Two-Wheel Drive High indicator light to stop flashing and remain on before shifting the transmission into gear.

Notice: Shifting the transmission into gear before the requested mode indicator light has stopped flashing could damage the transfer case. To help avoid damaging the vehicle, always wait for the mode indicator lights to stop flashing before shifting the transmission into gear.

It is typical for the vehicle to exhibit significant engagement noise and bump when shifting between Four-Wheel Drive Low and Four-Wheel Drive High ranges or from N (Neutral) with the engine running.

If the knob is turned to the Four-Wheel Drive High, AUTO, or Two-Wheel Drive High switch position when the vehicle is in gear and/or moving more than 5 km/h (3 mph), the Four-Wheel Drive High, AUTO or Two-Wheel Drive High indicator light will flash for 30 seconds but will not complete the shift.

Shifting into Neutral

To shift the transfer case to N (Neutral) do the following:

1. Make sure the vehicle is parked so that it will not roll.

2. Set the parking brake and apply the regular brake pedal. See Parking Brake on page 9‑58 for more information.

3. Start the vehicle or turn the ignition in ON/RUN.

4. Put the transmission in N (Neutral).

5. Shift the transfer case to Two-Wheel Drive High.

6. Turn the transfer case dial clockwise to N (Neutral) until it stops and hold it there until the N (Neutral) light starts blinking.

This will take at least 10 seconds. Then slowly release the dial to the four low position.

The N (Neutral) light will come on when the transfer case shift to N (Neutral) is complete.

7. If the engine is running, make sure that the transfer case is in N (Neutral) by shifting the transmission to R (Reverse) for one second, then shift the transmission to D (Drive) for one second.

8. Turn the ignition to ACC/ ACCESSORY, which will turn the engine off.

9. Place the transmission shift lever in P (Park).

10. Release the parking brake prior to moving the vehicle.

11. Turn the ignition to LOCK/OFF.

Shifting Out of Neutral

To shift out of N (Neutral) do the following:

1. Set the parking brake and apply the regular brake pedal.

2. Turn the ignition to ON/RUN with the engine off, and shift the transmission to N (Neutral).

3. Turn the transfer case dial to Two-Wheel Drive High, Four-Wheel Drive High, or AUTO.

After the transfer case has shifted out of N (Neutral), the N (Neutral) light will go out.

4. Release the parking brake prior to moving the vehicle.

Notice: Shifting the transmission into gear before the requested mode indicator light has stopped flashing could damage the transfer case. To help avoid damaging the vehicle, always wait for the mode indicator lights to stop flashing before shifting the transmission into gear.

5. Start the engine and shift the transmission to the desired position.


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