My TPMS Sensors all stopped working at once. My battery was getting a bit old. While the car always started, it was getting to the point that the seat would stop moving while cranking and it was cranking a little slow. I thought the low voltage while cranking was causing the computer to glitch. In fact sometimes if I shut off the car and restarted it the TPMS would start working again confirming my idea of the battery voltage issue. Today i put in a new battery and the TPMS did not come back to life as I had hoped :-( I tried the TPMUS relearn via the steering wheel controls. I hold the button on the TPMS relearn, but it does not seem to do anything. I plug my scan tool into it and I get a persistent C2126 error. The strange thing to me is that my scan tool can read the tire pressures, it just won't indicate on the dash. As my scan tool shows tire pressure, I assume the issue must be on the car computer side and not with the wheel sensors. The battery is now brand new with freshly cleaned terminals. Any thoughts on how to fix it?
Thanks!

 

this is the 3gs forum; it looks like you have a 4gs.

 

Doe! Your right! I'll repost in forth gen.

Thanks!

 

From some other posts I've found. I'm thinking this might be cold weather & old TPMS batteries. Thanks

 

Tire pressure sensor number 4 is not responding. Add 6 psi or more to the tires and check if the sensors respond promptly, the screen should update in less than 1 minute. You will likely need to replace all 4 sensors.