When you put new sensors on your Regal (or rotate the tires) you have to activate/relearn each sensor to each corner of the car (so the tire pressure/position screen is accurate).
YOU DON'T NEED THE TOOL, but it saves so much time.
** How to train sensors with the tool **
1. Press and hold the start button until the vehicle is in accessory mode.
2. Press the MENU button located on the turn signal lever until “VEHICLE INFORMATION MENU” is displayed.
3. Once you are in the VEHICLE INFORMATION MENU, use the ^ v on the turn signal level until the DIC displays the vehicle’s tire inflation pressure and positions.
4. Press and hold the button located on the end of the turn signal level until “Are you sure that you want to relearn? YES or NO” is displayed.
5. Use the ^ v on the turn signal lever to highlight YES. Once YES is highlighted, press the button located on the end of the turn signal lever. The horn will chirp, “Tire Learning Active” will be displayed on the DIC, and the left front turn signal will be illuminated.
6. Beginning with the left front frire, use a TPMS activation tool to activate the left front sensor. Once the sensor has been activated, the horn will chirp and the right front turn signal will be illuminated.Repeat procedure in the following order, right front sensor, right rear sensor, and finally the left rear sensor. Once the left rear sensor has been activated, the horn will chirp twice. You can then turn the vehicle off to exit “learn mode.”
IF YOU DON'T HAVE THE TOOL....... you put your Regal into “Tire Learning Active” mode and follow step 6. (Instead of pushing a button on the relearn tool, you will LET AIR/NITROGEN OUT/OR PUT IN (?) each tire until the horn chirps.
(I have not used this method, but many members have)