Q: After installing 2 new tires on the rear, the ESC Active light routinely comes on.

This is common anytime the wheels and tires are removed. Your car is equipped with wheel speed sensors at each of the four wheels which monitor wheel speed while relaying this information constantly to the ABS and traction control system which are controlled by the car’s ECU. When the ECU senses an abnormal speed given specific conditions, it engages the ABS or traction control as needed to control the vehicle properly and safely.

Occasionally, these sensors can fail or become faulty working intermittently sending inaccurate signals to the ECU. When this happens, you may experience the symptoms you have described. The ABS or traction control system may be inadvertently activated by these false or inaccurate signals. To avoid any unnecessary repairs. I would suggest having a professional from Your Mechanic come to your home to diagnose your ABS and traction control system and service your ABS speed sensor as necessary.