2012 GMC Canyon Owner's Manual - Page 210

9-38 Driving and Operating 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 5 km/h (3 mph) 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 1.6 to 3.2 km/h (1 to 2 mph). 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 5 km/h (3 mph), the Four-Wheel Low indicator light will flash for 30 seconds and not complete the shift. 4n (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. Shifting into Four‐Wheel Low will turn Traction Control and StabiliTrak® off. See Traction Control System (TCS) on page 9‑43 and StabiliTrak® System on page 9‑44 for more information. 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.