2006 Toyota Tacoma TPMs

My TPMS light is on, I've checked each sensor. The Rt. rear sensor and spare sensor have the same ID. Is there a way to change a sensors ID or does each sensor come with a fixed ID.

 

You mention that you "checked each sensor". How exactly did you check them?

Here's how it works. The sensors are 1 way communication. The truck listens to the information being sent to it by the sensors. The truck only listens to sensors it's been programmed to listen to. Let's call them Bob, Jake, Johnny, and Rafael. So, each sensor tells the truck what pressure is in the tire. Let's say they're all at 32. When you push the button, the truck learns that 32 is normal pressure and keeps the light off. Now, 1 morning Johnny is on a bad hangover and tells the truck he's only at 25PSI. The truck turns on the light to let you know. You give Johnny some pepto bismal(air), the truck is happy and turns out the light. On your way to work, there's a Tacoma beside you at the light with a low tire. That sensor is named Brittany. Your trucks light doesn't come on because your truck doesn't listen to Brittany.

So, when you get new sensors, there's 2 ways to make the truck happy.
1. Pull new OEM or aftermarket OEM type sensors off the shelf and program the truck to listen to them. Now the truck only listens to George, Paul, John, and Ringo. This programming can only be done by plugging into the truck OBD2 connector.

2. There are aftermarket sensors that have no name. It's like adopting a puppy at the shelter. Your dog Bob crosses over the rainbow bridge. You go to the shelter and adopt a new puppy and name him Bob. (The tire shop programs the nameless sensor to say, "Hi, my name is Bob") Now your truck still listens to Bob. Your truck isn't smart enough to realize it's a different Bob. He thinks it's the same old Bob, and is content and patiently waiting for Bob to go on a drinking binge.