Q: My car's tire pressure monitoring system lights come on when the tire pressure is normal

Your car is equipped with wheel speed sensors on each of the four wheels which monitor wheel speed while relaying this information to the ABS and traction control system (ESC) 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. Occasionally, these sensors can fail or only work 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.

Your TPMS system works the same way in that there are sensors that monitor the tire pressure relaying this to the car’s computer. These sensors are known to go bad occasionally. Keep in mind this can also fluctuate easily with changes in air temperature, as this changes the density of the air which will affect the way these sensors read tire pressure. With regard to your heater turning off and on, this may be related to the blower motor relay which is what directs power to the heater blower motor. When this is faulty, this may cause the blower fan to work intermittently or sometimes not at all. I would suggest having a professional, such as one from YourMechanic, diagnose your ABS and traction control system to determine the cause of this.