Chrysler Tire Airp pressure Sensors

My ?05 Chrysler Pacifica is equipped with tire pressure sensors. All 4 of my sensors don?t work, and the dealership wants nearly $500 to replace them. I think it should be covered under warranty. But they say blame the failure on changing the tires, done by Costco. I doubt they screwed up all 4 sensors, and they were not working before the tires were changed but I didn?t get it into the shop until after the tires were changed. Do I have any recourse?

So all 4 sensors were not working before you had the tires changed? Did it report low pressure on all 4 tires?