Review on Arozk TPMS Relearn Tool: GM Tire Pressure Monitor Sensor Programming & Activation OEC-T5 GL-50448 Auto Reset for GM Series Vehicles 2006-2021 by Paul Vanlaere

The block came in an open box, the block could not identify all 4 tires, there are no instructions in the box. Ordered a replacement and it came with Manuel's instructions. Failed to point the black antenna directly at the valve stem. That's not how it's programmed. You need to place the black antenna right on the edge of the rim as close to the valve stem as possible, press and release the TX button and it will flash for about 5 seconds. If you hold it in the right place, it will chirp. If you don't hold it in the right place, it won't recognize the tire. If you hold down the tx button until it appears, the device will stop working on the 2nd or 3rd bus. You have to press and release the button. When I placed it on the edge of the rim pointing directly at the tire just behind the valve stem I had no problem programming 2 separate cars back to back. If I held down the txt button instead of just pressing and releasing it, it wouldn't start all four buses every time. The instructions are vague at best so I've changed 4 from my original rating of 1. They sent me a replacement straight away and after I changed the procedures both work as advertised. They only transmit weakly, so it has to go through the bus. More expensive units are programmed to point at the valve stem, but this one is not.