How to Replace a Toyota Key Fob Battery
Match the stamp, fit one cell, and lock then unlock once from outside. A battery swap does not program the Toyota fob.
Replace and open
Replace and open is the work of getting the old cell out and a matching cell in. Shared opening steps live on the shell pages: coin notch, sliding latch, flip key, and remote head. Model pages point here instead of pasting those steps again. A new shape stays unconfirmed until the shell in your hand matches a known notch or latch. A battery-only swap does not require programming. Lock and unlock once from outside the car. Plus is the flat branded face unless a mark in the shell says otherwise. If a shell is a new shape, including a bZ4X, the older pry is not confirmed and is not reused. One cell is the normal count. The dead-smart-key start, for an owner still holding that fob, is a separate note: Park, brake, touch the fob to the button, then press. That is not a way to start a car without the fob.
How to Open a Toyota Key Fob
Open a coin notch, a sliding latch, a flip screw, or a remote-head screw. Do not reuse a Camry pry on a bZ4X or a new undocumented shell.
Start a Toyota with a Dead Key Fob
With the fob in hand, select Park, press the brake, touch the fob to the start button, then press. The stamp on the old cell wins.
Programming a Toyota Key Fob After a Battery Change
A Toyota battery change does not program the fob. A never-paired fob is a locksmith or dealer job. The stamp on the old cell wins.