Sounds like you’re frustrated. Here’s why—there is no fuel pump relay on the 2010 GMC Terrain. The fuel pump for the 2010 Terrain gets power from the chassis control module. The RUN/CRANK relay found in the fuse box under the hood sends power to the chassis control module.
To cut power to the fuel pump, you must remove the RUN/CRANK relay. You can locate that by referring to the fuse box diagram located under the fuse box lid or in your owner’s manual.
Generally, if your fuel pump relay is bad, your engine will turn but won’t start because fuel is not getting into the engine. But, because the GMC Terrain has no fuel pump relay, these issues may be connected to the RUN/CRANK relay. These could also be symptoms of other problems such as: