1995 GMC Sonoma Owner's Manual - Page 77

If the 4LO switchis pressed when your vehicle is in gear and/or moving, the amber 4LO indicator light flash for 30 seconds and not complete the will shift unless your vehicle is below 3 mph (4.8 km/h) and the transmission is in NEUTRAL (N) orthe clutch pedal depressed. On automatic transmission equipped vehicles: If your transfer case does not shift into 4L0, your transmission indicator switch may require adjustment. With your transmission in NEUTRAL (N), press and release the 4LO switch. Whilethe amber 4LO indicator light flashing, shift your is transmission into PARK (P). Wait until the 4LO indicator light goes solid amber before shifting your transmission into gear. This will get you into 4L0, but you should take your vehicle in for service so normal operation can be restored. To shift from4LO to 4HI -Your vehicle must be stopped or moving less than 3 mph (4.8 km/h) with the transmission in NEUTRAL (N) or the clutch pedal depressed. The preferred method for shifting out of 4LO is to have your vehicle slowly moving 1 to 2 mph (1.6 to 3.2 km/h). Press and release the 4HI switch. You must wait for the 4HI indicator light to stop flashing and go solid amber before shifting your transmission into gear or releasing the clutch pedal. If the 4HI switch is pressed when your vehicle is in gear and/or moving, the 4HI indicator light will flash for 30 seconds but not complete the shift unless the vehicle is below 3 mph (4.8 kmh) and the transmission is in NEUTRAL (N) or the clutch pedal depressed. On automatic transmission equipped vehicles: If your transfer case does not shift into 4H1, your transmission indicator switch may require adjustment. With your transmission in NEUTRAL (N), press and release the 4HI switch. While the 4HT indicator light is flashing, shift your transmission into PARK (P). Wait until the 4HI indicator light goes solid amberbefore shifting your transmission into gear. This will get you into 4H1, but you should take your vehicle in for service so normal operation can be restored. 2-31