How to determine which TPMS sensor is bad?

As I write this my 2007 Tacoma is at the dealer for a replacement TPMS and re-programming. I had a tire shop where I bought the tires replace a bad sensor with an aftermarket sensor on 1 tire. They couldn't get the ECU computer to accept the ID's from the 4 tires + spare even though all tires were transmitting a signal. Tried a 2nd tire shop (Discount) same deal. So reluctantly I took it to the Dealer. Come to find out that changing one sensor to aftermarket with the rest OEM will cancel out the other sensors in the Tacoma programming process. Have to make them all aftermarket or use an OEM sensor. Costing me twice as much for the OEM sensor and programming as the tire shop. Live and learn.

 

Start here: https://www.tacomaworld.com/threads/complete-tpms-disable-guide.161292/

Get a gauge, keep it in your glove box. Check your tire pressure occasionally while you are at the gas station - you will stay more on top of tire pressure than relying on the 2nd gen tpms system.