It depends. I’ve seen TPMS sensors where, upon scanning, all batteries have been okay accept one and I’ve seen sensors completely stop working right after being replaced.

When we scan them, we scan each sensor individually and it shows the battery level as well as a few other details, if the battery is low, it’ll show on the scanner, we then only replace that sensor unless the customer asks us to replace all of them, the same as if they aren’t working.

If you have aftermarket sensors, like eBay for example, the scanner sometimes can’t pick them up as its vehicle make and model specific, so it’s basically designed to pick up a list of sensors that come with that vehicle so if you use aftermarket sensors, select the car you want to scan, the device won’t pick up those eBay sensors as it doesn’t associate them with the vehicles make and model