How to Trigger a Non-programmable Sensor(Relearn TPMS sensors on a GM without the tool. For Most GM Vehicles with TPMS):
Step 1: Turn the key to accessory position.
Step 2: On the fob, hold down the lock and unlock until the dash display says "Tire Learn Active." Leave the key in accessory position while performing the following steps. Do not shut the door as the car doors will lock during the process.
Step 3: Turn clockwise to the front driver, front passenger, rear passenger, driver's rear tire, and then release the air until the car horn sounds. It should be kept 2 times. Readjust tire pressure at each to proper level.