GM Service Manual Online
For 1990-2009 cars only

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 best performance out of four-wheel drive, you must be familiar with its operation. Read this section before using four-wheel drive. You should use two-wheel-drive high for most normal driving conditions.

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: If the vehicle has four-wheel drive and the different size spare tire is installed on the vehicle, do not drive in four-wheel drive until you can have your flat tire repaired and/or replaced. You could damage the vehicle, and the repair costs would not be covered by your warranty. Never use four-wheel drive when the different size spare tire is installed on the vehicle.

Notice: If the vehicle has four-wheel drive and the compact spare tire is installed on the vehicle, do not drive in four-wheel drive until you can have the flat tire repaired and/or replaced. You could damage the vehicle, and the repair costs would not be covered by your warranty. Never use four-wheel drive when the compact spare tire is installed on the vehicle.


Object Number: 1306915  Size: B2

The transfer case buttons are located to the right of the steering wheel on the instrument panel.

Recommended Transfer Case Settings

Driving Conditions

Transfer Case Settings

2

4

4

N

Normal

YES

 

 

 

Severe

 

YES

 

 

Extreme

 

 

YES

 

Vehicle in Tow*

 

 

 

YES

*See Recreational Vehicle Towing or Towing Your Vehicle for further information.

Use these buttons to shift into and out of four-wheel drive. You can choose from the following:

2 (Two-Wheel High): This setting is for driving in most street and highway situations. The front axle is not engaged in two-wheel drive.

Caution: Shifting the transfer case to Neutral can cause the vehicle to roll even if the transmission is in P (Park), or if you have a manual transmission, even if you are in gear. You or someone else could be seriously injured. Be sure to set the parking brake before placing the transfer case in Neutral. See Parking Brake.

N (NEUTRAL):  Shift the vehicle's transfer case to NEUTRAL only when towing the vehicle.

4 (Four-Wheel High): This setting engages the front axle to help drive the vehicle. Use four-wheel high when you need extra traction, such as on snowy or icy roads, or in most off-road situations.

4 (Four-Wheel Low):  This setting also engages the front axle to give you extra traction. It sends the maximum power to all four wheels. You might choose four-wheel low if you were driving off-road in sand, mud, or deep snow and while climbing or descending steep hills. Indicator lights in the buttons show you which setting you are in. The indicator lights will come on briefly when you turn on the ignition and one will stay on the selected setting. If the lights do not come on, you should take the vehicle in for service. An indicator light will flash while shifting. It will stay on when the shift is completed. If the transfer case does not shift, it will return to the last chosen setting.

Shifting from Two-Wheel High to Four-Wheel High

Press and release the Four-Wheel High button. This can be done at any speed, and the front axle will lock automatically.

Shifting from Four-Wheel High to Two-Wheel High

Press and release the Two-Wheel High button. This can be done at any speed, and the front axle will unlock automatically.

It is normal to hear and feel the vehicle's transfer case shift into Four-Wheel High. If you shift with the vehicle stopped, the indicator light may still flash slowly. It may be necessary to shift the transmission momentarily into R (Reverse) and D (Drive), for an automatic transmission, or R (Reverse) and 1 (First) for a manual transmission to have the light stop flashing.

Shifting from Two-Wheel High or Four-Wheel High to Four-Wheel Low

To shift from Two-Wheel High or Four-Wheel High to Four-Wheel Low, the vehicle must be stopped or moving less than 3 mph (5 km/h) with the transmission in N (Neutral) for an automatic transmission or the clutch pedal pressed for a manual transmission. The preferred method for shifting into Four-Wheel Low is to have your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h).

Press and release the Four-Wheel Low button. You must wait for the Four-Wheel Low indicator light to stop flashing and stay on before shifting the transmission into gear or releasing the clutch pedal.

If the Four-Wheel Low button is pressed when the vehicle is in gear and/or moving faster than 3 mph (5 km/h), the four-wheel low indicator light will flash for 30 seconds and not complete the shift.

Shifting from Four-Wheel Low to Two-Wheel High or Four-Wheel High

To shift from Four-Wheel Low to Two-Wheel High or Four-Wheel High, the vehicle must be stopped or moving less than 3 mph (5 km/h) with the transmission in N (Neutral) for an automatic transmission or the clutch pedal pressed for a manual transmission. The preferred method for shifting out of four-wheel low is to have your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h).

Press and release the Four-Wheel High or Two-Wheel High button. You must wait for the Four-Wheel High or Two-Wheel High indicator light to stop flashing and stay on before shifting the transmission into gear or releasing the clutch pedal.

If the Four-Wheel High or Two-Wheel High button is pressed when the vehicle is in gear and/or moving faster than 3 mph (5km/h), the Four-Wheel High or Two Wheel High indicator light will flash for 30 seconds but not complete the shift.

Shifting to NEUTRAL

Use NEUTRAL when you plan to tow the vehicle. See Recreational Vehicle Towing for towing instructions. To shift the transfer case into NEUTRAL do the following:

  1. Set the parking brake.
  2. Start the vehicle.
  3. Press the regular brake pedal and shift the transmission in N (Neutral), or press in the clutch for vehicles with a manual transmission.
  4. Shift the transfer case to Two-Wheel High.
  5. Press and hold the Two-Wheel High and Four-Wheel Low buttons at the same time for 10 seconds. The N (Neutral) light will come on when the transfer case shift to N (Neutral) is complete.
  6. Press and hold the regular brake pedal and shift the transmission to R (Reverse) for one second, then shift the transmission to D (Drive) for one second, or 1 (First) for vehicles with manual transmissions, and let out the clutch to insure the transfer case is in NEUTRAL. If the transfer case is not in NEUTRAL, repeat this procedure starting at Step 3.
  7. Turn the engine off by turning the key to ACC/ACCESSORY.
  8. Place the transmission shift lever in P (Park), or 1 (First) for vehicles that have a manual transmission.
  9. Turn the ignition to LOCK/OFF.

Shifting Out of NEUTRAL

After towing the vehicle, you will have to shift out of NEUTRAL in order to drive. To shift out of NEUTRAL, do the following:

  1. Set the parking brake and apply the regular brake pedal.
  2. Start a vehicle with an automatic transmission in P (Park). Use 1 (First) for vehicles with a manual transmission.
  3. Shift the transmission to N (Neutral), or press the clutch pedal for vehicles with a manual transmission.
  4. Press the button for the desired transfer case shift position (Two-Wheel High, Four-Wheel High, or Four-Wheel Low).
  5. After the transfer case has shifted out of NEUTRAL, the indicator light will go out.
  6. Release the parking brake.
  7. Shift the transmission to the desired position.