See also:

Engine Cooling System Messages
ENGINE HOT A/C (Air Conditioning) TURNED OFF This message displays when the engine coolant becomes hotter than the normal operating temperature. See Engine Coolant Temperature Gauge on page 5‑ ...

Under the Hood
The Yukon Hybrid uses a two-mode hybrid system. The system augments the SUV's V-8 engine with two electric motors, both powered by a 300-volt battery pack. A cylinder-deactivation system cuts powe ...

How OnStar Service Works
Automatic Crash Response, Emergency Services, Crisis Assist, Stolen Vehicle Assistance, Vehicle Diagnostics, Remote Door Unlock, Roadside Assistance, Turn-by-Turn Navigation, and Hands-Free Callin ...