GMC Terrain Quiz
Driving and Operation

Diesel Exhaust Fluid

In this manual: Driving and Operation
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. Products such as AdBlue are types of DEF and are approved for use in this vehicle as long as they have the API certification label or meet ISO 22241 standard. The DEF tank fluid level must be maintained for the vehicle to operate properly. DEF is not a fuel additive. DEF must never be mixed with or added to diesel fuel. DEF freezes at temperatures below -11 °C (12 °F).

It is normal to hear the DEF system drain fluid back into the tank after the vehicle is turned off.

Finding Diesel Exhaust Fluid

DEF can be purchased from your dealer. It is also available at authorized GM car and truck dealers. In addition, some diesel truck fueling stations or retailers may have DEF for purchase. For vehicles with an active OnStar or connected services plan, OnStar can help locate a DEF distributor. See Customer Assistance Offices for phone numbers to help contact a GM dealer. See Recommended Fluids and Lubricants.

Test yourself

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