GMC Terrain: Driving and Operating / Diesel Particulate Filter

The Diesel Particulate Filter (DPF) system filters soot particles out of the exhaust gases. The DPF is under the vehicle in the exhaust system.

Depending on a number of factors monitored by the engine computer, the DPF will need to be cleaned of accumulated solids. When a cleaning is needed, the engine computer will initiate a self-cleaning function that runs automatically during driving without any notification. The filter is cleaned by periodically burning off the soot particles at high temperature. This process takes place automatically under set driving conditions and may take up to 25 minutes. Fuel consumption may be higher during this period.

While the DPF cleaning is automatically controlled by the engine computer, the vehicle will need to operate continuously for approximately 25 minutes and at speeds greater than 50 km/h (30 mph) to clean the DPF effectively.

If the vehicle is used for numerous short trips or extended slow-speed operation, the engine computer may not be able to adequately heat up the exhaust system to clean the DPF effectively. The engine computer has been designed to continuously monitor the condition of the DPF. When the engine computer detects that the DPF is nearly full of particulates and that the vehicle is not being operated in a manner that would allow effective automatic DPF cleaning, a Driver Information Center (DIC) message will display. Start the cleaning process as soon as possible.

Cleaning Process

To activate the cleaning process, continue driving safely, and keep vehicle speed above 50 km/h (30 mph) until the warning message in the DIC turns off.

If the vehicle continues to be driven with the DPF warning message on, and the exhaust filter is not cleaned as required, the malfunction indicator lamp and the ENGINE POWER IS REDUCED message will come on. Dealer service is necessary.

See Malfunction Indicator Lamp (Check Engine Light).


During DPF self cleaning or during extended idling while parked, the exhaust system and exhaust gases are very hot. Things that burn could touch hot exhaust parts under the vehicle and ignite. You or others could be burned. Do not park, or idle for an extended period of time, near or over papers, leaves, dry grass, or other things that can burn. Keep the exhaust area clear of material that could ignite or burn. See Parking over Things That Burn for more information.

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