GM Service Manual Online
For 1990-2009 cars only

If your vehicle has four-wheel drive, you can send your 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 part that follows before using four-wheel drive. You should use two-wheel-drive high (2HI) 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.


Object Number: 1306915  Size: B2

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

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

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

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

Caution: Shifting the transfer case to 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 Neutral. See Parking Brake.

4(4HI): This setting engages your front axle to help drive your vehicle. Use 4HI when you need extra traction, such as on snowy or icy roads, or in most off-road situations.

4(4LO):  This setting also engages your front axle to give you extra traction. It sends the maximum power to all four wheels. You might choose 4LO if you were driving off-road in sand, mud or deep snow and 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. If the lights do not come on, you should take your vehicle in for service. An indicator light will flash while shifting. It will remain illuminated when the shift is completed. If for some reason the transfer case cannot make a requested shift, it will return to the last chosen setting.

Shifting from 2HI to 4HI

Press and release the 4HI button. This can be done at any speed, and the front axle will lock automatically.

Shifting from 4HI to 2HI

Press and release the 2HI button. This can be done at any speed, and the front axle will unlock automatically.

Shifting from 2HI or 4HI to 4LO

To shift from 2HI or 4HI to 4LO, the vehicle must be stopped or moving less than 1.2 mph (2 km/h) with the transmission in NEUTRAL (N) in vehicles equipped with an automatic transmission or the clutch pedal engaged in vehicles equipped with a manual transmission. The preferred method for shifting into 4LO is to have your vehicle moving 1.2 mph (2 km/h). Press and release the 4LO button. You must wait for the 4LO indicator light to stop flashing and remain illuminated before shifting your transmission into gear or releasing the clutch pedal.

If the 4LO button is pressed when your vehicle is in gear and/or moving faster than 1.2 mph (2 km/h), the 4LO indicator light will flash for 30 seconds and not complete the shift.

On automatic transmission equipped vehicles, if your transfer case does not shift into 4LO, your transmission indicator switch may require adjustment. With your transmission in NEUTRAL (N), press and release the 4LO button. While the 4LO indicator light is flashing, shift your transmission into PARK (P). Press 4LO again. Wait until the 4LO indicator light remains illuminated before shifting your transmission into gear. Press the 4LO button again to complete the shift. This will get you into 4LO, but you should take your vehicle in for service to restore normal operation.

Shifting from 4LO to 2HI or 4HI

To shift from 4LO to 2HI or 4HI, your vehicle must be stopped or moving less than 1.2 mph (2 km/h) with the transmission in NEUTRAL (N) or the clutch pedal engaged. The preferred method for shifting out of 4LO is to have your vehicle moving 1.2 mph (2 km/h). Press and release the 4HI button. You must wait for the 4HI indicator light to stop flashing and remain illuminated before shifting your transmission into gear or releasing the clutch pedal.

If the 4HI button is pressed when your vehicle is in gear and/or moving faster than 1.2 mph (2 km/h), the 4HI indicator light will flash for 30 seconds but not complete the shift.

On vehicles with an automatic transmission, if your transfer case does not shift into 4HI, your transmission indicator switch may require adjustment. With your transmission in NEUTRAL (N), press and release the 4HI button. While the 4HI indicator light is flashing, shift your transmission into PARK (P). Wait until the 4HI indicator light remains illuminated before shifting your transmission into gear. Press the 4HI button again to complete the shift. This will get you into 4HI, but you should take your vehicle in for service to restore normal operation.

Shifting to NEUTRAL

Use NEUTRAL when you plan to tow your 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. Connect the vehicle to the towing vehicle.
  4. Shift the transmission in Neutral (N), or press in the clutch for vehicles with a manual transmission.
  5. Shift the transfer case to 2HI.
  6. Press and hold the 2HI and 4LO buttons at the same time for 10 seconds. The Neutral (N) light will come on when the transfer case shift to Neutral (N) is complete.
  7. Shift the transmission to Reverse (R) for one second, then shift the transmission to DRIVE (D) for one second, or FIRST (1) for vehicles with manual transmissions.
  8. Turn the ignition to LOCK.
  9. Place the transmission shift lever in Park (P), or FIRST (1) for vehicles equipped with a manual transmission.
  10. Release the parking brake prior to towing.

Shifting out of NEUTRAL

After towing your 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. See Parking Brake for more information.
  2. Start a vehicle with an automatic transmission in PARK (P). Use FIRST (1) for vehicles with a manual transmission.
  3. Put an automatic transmission in NEUTRAL (N) or press the clutch pedal for vehicles with a manual transmission.
  4. Press the button for the desired transfer case position (2HI, 4HI or 4LO).
  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 gear.

It is normal for your vehicle to exhibit a significant engagement noise and bump when shifting in and out of Neutral (N) and 4LO.