The vehicle must be on a level surface when checking the coolant level.
It is normal to see coolant moving in the upper coolant hose return line when the engine is running.
Check to see if coolant is visible in the coolant surge tank. If the coolant inside the coolant surge tank is boiling, do not do anything else until it cools down.

If coolant is visible but the coolant level is not at or above the mark pointed to, add a 50/50 mixture of clean drinkable water and DEX-COOL coolant.
Be sure the cooling system is cool before this is done.
What to Use
How to Add Coolant to the Coolant Surge TankSmartphone Link (Stitcher)
Some images and explanations may vary by phone operating systems, versions, and/or
application (App) versions.
Using Stitcher
Install the Stitcher application on the smartphone.
Connect the smartphone to the infotainment system through the USB port or
Bluetooth wireless technology.
...
Menu System
Controls
The MENU/TUNE knob and BACK button
are used to navigate the menu system.
MENU/TUNE Knob:
Turn to:
Highlight a menu option.
Select a value.
Press to:
Enter the menu system.
Select or activate the highlighted menu option.
Confirm a set value.
Turn a system setting on ...
Reduced Engine Power Light
The reduced engine power light should
come on briefly as the engine is started. If it does not come on, have the vehicle
serviced by your dealer.
This light, along with the malfunction indicator lamp, displays when a noticeable
reduction in the vehicle's performance occurs.
The vehicle c ...