GMC Terrain Quiz
In Brief

Diesel Exhaust Fluid

In this manual: In Brief
Introduction — 1In Brief — 46Keys, Doors and Windows — 37Seats and Restraints — 60Storage — 6Instruments and Controls — 58Lighting — 16Infotainment System — 1Climate Control — 8Driving and Operation — 128Vehicle Care — 75Service and Maintenance — 8Technical Data — 5Customer Information — 18OnStar — 6Connected Services — 4
~1min read

Diesel Exhaust Fluid (DEF) is used with diesel engines to reduce the amount of regulated emissions produced. The DEF system must be maintained for the vehicle to operate properly. It is normal to hear the DEF system purging fluid back into the tank after the vehicle is turned off.

Finding Diesel Exhaust Fluid

DEF can be purchased at a GMC dealer. It can also be purchased at authorized dealerships. In addition, some diesel fuel stations or retailers may carry DEF. For vehicles with an active OnStar plan, OnStar can help locate a DEF retailer. Refer to Customer Assistance Offices for telephone numbers to contact a GM dealer. Refer to Recommended Fluids and Lubricants.

When the DEF tank is low, warnings begin at approximately 1600 km (1000 miles) of remaining range. These warnings will increase as the tank becomes empty. Once the tank is empty, the vehicle speed will be limited. If there is a problem with the quality of the exhaust fluid or the exhaust fluid, warnings will be displayed in the Driver Information Center (DIC). Refer to Diesel Exhaust Fluid.

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A quick GMC Terrain quiz: every answer comes with an explanation and a link to the manual page.