How to Jump Start a GMC Terrain

1. Check that the other vehicle has a 12-volt battery with a negative ground system, and park the two vehicles so they do not touch.
2. Set the parking brake, turn the vehicle off, and turn off all lights and accessories in both vehicles except hazard flashers if needed.
3. Check that the jumper cables have no loose or missing insulation.
4. Connect one end of the red positive (+) cable to the discharged battery positive (+) terminal, which is under a trim cover.
5. Connect the other end of the red positive (+) cable to the good battery positive (+) terminal.
6. Connect one end of the black negative (–) cable to the good battery negative (–) terminal.
7. Connect the other black negative (–) end to the discharged battery negative (–) grounding point, then run the good vehicle's engine at idle for at least four minutes.
8. Try to start the vehicle with the dead battery; if it will not start after a few tries, it probably needs service.

• Connecting or removing the cables in the wrong order can cause electrical shorting and damage not covered by the warranty.
• To remove the cables, reverse Steps 6–9 in exact order, then let the started vehicle idle for several minutes.
• The discharged battery grounding point and positive terminal are on the driver side of the vehicle.

Source: 2026 GMC Terrain owner's manual, PDF pages 267, 268. Steps are summarized in our own words (AI-assisted, checked against the cited pages 2026-10-18). Other model years can differ; your manual has the final word.