Monica Sanchez start off by trying to reset the TPMS :
WITH STANDARD IGNITION:
1. Apply parking brake.
2. Turn ignition to ON position (engine off)
3. Press the MENU button on the DIC (located on instrument cluster for all others) until the vehicle's tire pressures are displayed.
4. Press Set/Cir . Vehicle asks “Are you sure that you want to relearn?” Select Yes.
5. Starting at LF tire, decrease air pressure until horn chirps. Repeat procedure for remaining tires in the following order: RF, RR, and LR. After completing LR tire, horn will sound twice.
6. Turn ignition to OFF position to exit vehicle learn mode. Adjust all tires to pressure listed on tire placard.
WITH PUSH-BUTTON START:
1. Press and hold the push button start until the vehicle is in accessory mode. Note: on Cadillac models you will know when you are in accessory mode the Cadillac emblem appears on the DIC.
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 tire, 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.”