If you do not have enough things to worry about on your car’s dash, there is another light to look for. Beginning in car model years 2005, there is a system to monitor the tire pressures with the resulting light on the dash. This is a federal program that came about as a result of the Ford and Firestone tire fiasco; yet another government effort to protect us. This covers all passenger cars and certain GVW pickups. Each car manufacturer uses slightly different means to sense the tire pressures, causing various problems and corrections; plus this is an ever changing technology. Please stay tuned.
The more common sensor incorporates the valve stem with a transmitter. The car’s computer reads the signal and if pressures are out of range the light will be on. Other systems base the readings on variance in the speed of each wheel as the signal, like the antilock brake sensors. A few systems will display which tire is low and some even monitor the spare tire pressure. Each of these versions has its own problems and costs involved.
The first step if the light is on is to check the condition of the tires. Is there a puncture, if so repair the tire and reset the light. The sensors that are the valve stem have several problem areas. They must seal against the wheel, the core must be clean and function properly. Most of these are made of aluminum and will corrode over time and be replaced, they can also break. Tiny batteries power these sensors and will fail in time, again the sensor must be replaced. The cost of the sensors run from $50-$200, plus in a few cases a cost to reset the computer. Some models reset while driving while some require a computer reset with specialized equipment.
What do you do with these sensors? First, if the light comes on have the tires checked and repaired if needed. Do not assume the tires are inflated improperly. Have the light reset as needed. Second, when you buy new tires have the sensors serviced especially if they are the valve stem variety. Be aware that these have been extremely sensitive and finicky, with many false alarms. Also, plan on regular maintenance of these sensors and be prepared for some unexpected, additional costs.