Tire pressure monitor system malfunctioning
 

Took my car to have the wheels aligned, a brake job on the front axle, the tires rotated, and a tire air leak repaired. Ever since then, the tire pressure sensors randomly don’t display the pressure for some or all the tires especially in cold weather. Sometimes the pressure appears for all tires, sometimes for only some, sometimes for none at all. The car was actually pretty screwed up when I left the repair shop: the brake's rumbled when applied, the car still pulled to the left, and the tire still leaked.

So, I went back to a different location in the same chain. They told me that the tire pressure sensors operated on individual battery and they are probably going dead. If the car itself has a battery, this doesn’t make any sense to me. Besides, why did they suddenly go out only when I got service from them?

Is what the technician is telling me correct, or is he blowing smoke?

The sensor is located in the wheel and is not physically connected to the car's battery, so it has its own button battery. The lifespan of such batteries is 8-20 years, depending on the manufacturer. The fact that the car is pulled and the tires are leaking is certainly the shop's fault. But the tire pressure sensors failing is 100% due to age.