I have read that if you don't have the caps on it will affect the readings. Make sure you have caps on all 5 tires. If that doesn't work try re-training it with the magnate.

While driving home yesterday, I heard a ding and saw the orange flat-tire indicator light up. I didn't feel like I had a flat, so I looked up at the EVIC, which said "Check TPM System". I tried turning the ignition off and on again, and I did inspect all the valves, they seemed fine, no visible damage (although one of the caps was missing, so I took the one off the spare to replace it). This morning it was still complaining of it, but about halfway to work it stopped. Anybody ever see this error before and know what to look for? I want to believe it's just the valve cap, but if it's something else, I wonder if I should bring it in.