2008 GMC Envoy Owner's Manual - Page 283

Overload Protection The air suspension system is equipped with overload protection. Overload protection is designed to protect the air suspension system, and it is an indicator to the driver that the vehicle is overloaded. When the overload protection mode is on, it will not allow damage to the air compressor. However, do not overload the vehicle. See Loading Your Vehicle on page 4-34. If the suspension remains at a low height, the rear axle load has exceeded GAWR (Gross Axle Weight Rating). When the overload protection mode is activated, the compressor operates for about 30 seconds to one minute without raising the vehicle depending on the amount of overload. This will continue each time the ignition is turned on until the rear axle load is reduced below GAWR. Towing a Trailer {CAUTION: If you do not use the correct equipment and drive properly, you can lose control when you pull a trailer. For example, if the trailer is too heavy, the brakes may not work well - or even at all. You and your passengers could be seriously injured. You may also damage your vehicle; the resulting repairs would not be covered by your warranty. Pull a trailer only if you have followed all the steps in this section. Ask your dealer/retailer for advice and information about towing a trailer with your vehicle. Notice: Pulling a trailer improperly can damage your vehicle and result in costly repairs that would not be covered by your warranty. Always follow the instructions in this section and check with your dealer/retailer for more information about towing a trailer with your vehicle. To identify the trailering capacity of your vehicle, you should read the information in "Weight of the Trailer" that appears later in this section. 4-45 Indicator Light The indicator light on the inflator switch in the rear passenger compartment also serves as an indicator for internal system error. If the indicator light is flashing without the load leveling function or the inflator being active, turn off the ignition. The next day turn on the ignition and check the indicator light. The vehicle can be driven with the light flashing, but if it is you should have the vehicle serviced as soon as possible.