Did you set it in program mode?
With Standard Ignition.
1. Inflate all tires to pressure listed on tire placard
2. Turn ignition to OFF position and press and release brake pedal.
3. Cycle ignition from OFF to RUN position 3 times, ending in RUN position.
4. Press and release brake pedal.
5. Turn ignition to OFF position.
6. Cycle ignition from OFF to RUN position 3 times, ending in RUN position.
7. Horn will sound once and TPMS telltale will blink once train mode is initiated. If equipped with message center, it will display TRAIN LF TIRE. Place antennae of learn tool on sidewall of LF tire 180 degrees from valve stem to activate sensor. Horn will sound once sensor has been recognized, Repeat step for RF, RR, and LR tires.
8. After training LR tire the message center will display TRAINING MODE COMPLETE. If the vehicle is not equipped with the message center display, successful completion can be verified by turning the ignition to the OFF position and not hearing the horn sound. If the horn sounds, the training procedure must be repeated.
You shouldnt have to re train the sensors unless you have swapped them out.
The letting the air out trick doesnt work on the 06 +