One dead sensor usually means the other sensors are likely to fail soon. TPMS batteries are sealed inside the sensor. They are not replaceable. Typical OE sensor life is 7–10 years. When one sensor dies of old age, the other three are usually the same vintage.
Replacing only the failed unit often means the customer is back in a few months. Replacing all four at once is more convenient for the vehicle owner and more profitable for the shop. The vehicle leaves with a matched set, the relearn is done once, and you avoid a second teardown.
REDI-Sensor makes that recommendation easier to execute. You do not need to source or stock four different OE sensors. The four multi-application REDI-Sensor SKUs will cover the vast majority of the vehicles that come in. If you explain battery lifetime and the advantage of one service visit over four separate visits, you may be able to convince your customer to replace all four sensors in one service.
