The 2013 Chevy Cruze indoor regulator is in the indoor regulator lodging on the lower coolant line. The indoor regulator estimates the temperature of the coolant going through the line</br> and from that point it can figure out what temp the motor is running at. In the event that this part isn't working then the motor risks overheating</br> which is awful for the vehicle. In the event that a motor overheats it will risk twisting or breaking the head gasket</br> which will cost thousands to fix over the long haul. Assuming that You get a check motor light letting you know that the indoor regulator isn't working then sort it out immediately. It is around 200 for a full substitution so You would rather not stand by.