Hello guys…
Just got back from our first long road trip and had the chance to use all the features in our car. We noticed something strange—our car would beep at us when we changed lanes without signaling.
My dad also noticed that it would pull like I’m used to, but it would beep too. The guy I bought the car from mentioned that lane keep assist wouldn’t beep at you.
So, what exactly is this feature doing then? The sales guy couldn’t give me a clear answer! 
As per the instructions on page 245 (page 246 on the attached PDF file), the Lane Keep Assist is capable of emitting three alarms.
If a detected lane marking is approaching the car, LKA may help by gently rotating the steering wheel. If the car passes a detected lane marking, it could additionally flash Amber to indicate a Lane Departure Warning (LDW). In addition, depending on the direction of lane departure, there can be three beeps or three pulses on the driver’s seat, either on the right or left.
HI… Your Chevy Equinox may beep due to various reasons such as seat belt reminders, door or trunk ajar warnings, low fuel, or maintenance alerts. Check the vehicle’s dashboard for specific indicators.
I’m grateful. I recently realized that I was also never given a manual! I must inquire as to its location.
The mystery is solved.
It could be an Open Door Reminder. Some automobiles feature a reminder device that sounds when you turn off the engine while one of the doors is still open. This is a safety function that prevents you from leaving the doors open and draining the vehicle’s battery.