Saturday. Got out of the gym and started my 2015 Chevy Sonic RS Hatchback to head to Publix (about five minutes drive away). Was driving in the city about 35 mph. Got to a stop light and was waiting for about 10 seconds for green. Suddenly the Temperature Gauge Light comes on and a loud beeping goes off in the cabin of the car. I pulled over once the light went green, looked in the manual, and it said to turn the heaters up all the way as a temporary fix. Also had other info such as: check coolant levels, don't open the coolant cap until car has been stationary for a long time, etc.

I turned the heater up all the way, and no heat was coming inside the vehicle at all. Weird. Instead, I got a slightly worrying smell. Like burning? Chemical-ish? After waiting for a bit, I started the car again and drove. I got to Publix, and the beeping and flashing happened again just as I got into a spot to park. I got out and opened to hood. The car was HOT. I had only driven about 5 minutes, and it was a cool day. I sat in my car and googled with no information that was very helpful to aid me. Ended up calling my local Chevrolet Dealer's Service Team, and they booked me in the upcoming Monday. On the way home from Publix, the Temperature Light came on three times. I pulled over and sat each time for about fifteen minutes to let it cool.

Jumping to Monday Morning at 6:20AM heading to the Chevrolet Dealer: Cold, cold morning. So happy that I have heated seats. I turned the heat up all the way, as per manual instructions. The Dealer was about 15 minutes away. The beeping and flashing Temperature Light in the car happened twice. Each time, I pulled over and turned the car off and sat for about fifteen minutes to let the car cool and then proceeded to move again. When I arrived, I could hear a fan running loudly even after I turned the car off. I arrived waaay before my appointment, but I just wanted to make sure I could have time incase an emergency happened or my car had to stop more than five times (calculated: 15 minutes each stop of waiting for car to cool = 75 minutes waiting in car). This car is basically new, less than 25,000 miles on it! Why so many problems!? I really want to love my Chevy. (Other issues explained elsewhere: Electrical ABS light on issue, Traction Control light on issue, Collision Alert coming on with no other cars around, Complete Hub replacement, etc.)

I spoke with the Certified Mechanic, Josh, who I have gotten to know well due to the fact that I have had to bring my car in so many times while it is still under warranty. I got a loaner Chevrolet Malibu to utilize. The Service Team is Fantastic there. I got a call about five hours later that Josh found the issue. He said the ENTIRE Radiator needed to be replaced. They had one in store, so he was going to have it done before the day ended and address the other issues I also added on (Collision Alert coming on without cars around and heater not working). Waiting to hear back on those additional issues soon.

SO FANTASTIC! It's covered under the warranty, but it still made me miss an hour and a half of work and go out of my way to solve. A new-ish car shouldn't have these issues. How much would this have cost AFTER my warranty ran out?

TL;DR: Temperature Light kept flashing on 2015 Chevy Sonic RS. Car was overheating at stop lights and slow-driving traffic/randomly. I called the Chevrolet Certified Service Team in my area. Took my car in. Whole Radiator had to be replaced under warranty.