Replacement is a swap of the stamped cell, then a lock and unlock from outside. The cell usually fitted is a CR2032 in a smart key or a CR2016 in an older remote-head or flip key, and the key is a smart key, flip key, or remote-head key. People who searched how to replace a toyota key fob battery still have one rule to follow. If a chart disagrees, the stamp on the old cell wins.
Read the stamp before a cell swap
The coin already in the shell is the buying guide for a cell swap.
CR1632 is reported for a cell swap on some mid-generation smart keys, including certain Prius shells.
The CR2016 you might buy for a cell swap is 20 mm across and 1.6 mm thick.
Every one of those coins, in the case of a cell swap, is a 3-volt lithium cell.
A rechargeable LIR2032 does not belong in the shell for a cell swap.
A mark molded into the plastic wins over habit during a cell swap.
Right-hand drive does not change the coin you buy for a cell swap.
Touching a dead smart key to the start button is a separate backup, not the shopping step in a cell swap.
Close the cover fully before you test a cell swap from outside the car.
A brochure can list two keys for one car, and a cell swap still follows the shell you are holding.
If the shell in a cell swap is a new undocumented shape, the pry method is not confirmed.
Take the old cell out before you buy, and match its stamp.
That confirm step does not program the fob.
Match the cell for a cell swap
A push-button smart key from the 2010s onward usually takes a CR2032 when you are doing a cell swap.
If two reliable notes disagree about a cell swap, the page says they disagree.
The CR2025 you might buy for a cell swap is 20 mm across and 2.5 mm thick.
Same voltage does not make the coins interchangeable for a cell swap.
Almost every Toyota fob takes one cell, and a cell swap is not a two-cell case.
A battery-only swap for a cell swap does not require programming.
Base grades often kept a metal key after a higher grade moved on, which still matters for a cell swap.
Keep the spare coin for a cell swap in a cool drawer, not on a dashboard.
A gap at the cover, during a cell swap, means the coin is too thick or a clip missed.
Japan, Australia, Europe, and the US can print different grade names around a cell swap.
A bZ4X-style shell is not opened with an older Camry method during a cell swap.
Seat one cell only. The flat branded face is plus unless the shell mark says otherwise.
If nothing happens, reseat the cell before you blame the car.
Keep the wrong parts out of a cell swap
An older remote-head key or flip key usually takes a CR2016 when you are doing a cell swap.
CR1616 is uncommon for a cell swap and is not the default older Toyota cell.
A CR1632 reported for a cell swap is 16 mm across and 3.2 mm thick.
A CR2450 is the wrong coin for a cell swap.
This site does not invent a two-battery fob for a cell swap.
After a cell swap, lock the car once from outside and then unlock it once.
Grade names used for a cell swap belong to that market, not to a borrowed US list.
A pharmacy coin and a dealer coin are the same job for a cell swap when the stamp matches.
Do not stack a second coin as a shortcut for a cell swap.
The work of a cell swap stays a cell swap on a hybrid.
If the stamped coin is seated and a cell swap still fails, the fob has failed. Stop.
Close the cover square. A gap means the cell is too thick or a clip missed.
A plastic tab left on a new cell will leave the buttons dead.
Close the shell after a cell swap
CR2025 appears for a cell swap only on some older compact remotes.
The CR2032 you might buy for a cell swap is 20 mm across and 3.2 mm thick.
A CR1616, uncommon for a cell swap, is 16 mm across and 1.6 mm thick.
An A23 battery is the wrong shape for a cell swap.
Plus, while you handle a cell swap, is the flat branded face unless the shell mark disagrees.
A hybrid badge does not change the coin you buy for a cell swap.
A never-paired extra fob is outside a cell swap. A dealer or licensed locksmith does that work.
A date code on the blister for a cell swap tells you the coin is fresh. It does not choose the size.
Do not slip foil under the coin as a shortcut for a cell swap.
The work of a cell swap stays a cell swap on a right-hand-drive car.
Write the stamp on the spare sleeve when you finish a cell swap.
Stand outside and press lock, then unlock, once.
The emergency blade, if the shell has one, slides out before some smart keys will open.
Pages that sit beside a cell swap
Continue with the write-up on What Battery Does a Toyota Key Fob Take.
Continue with notes for How to Open a Toyota Key Fob.
Continue with Toyota Key Fob Battery Polarity.
Continue with the page Start a Toyota with a Dead Key Fob.
Continue with the write-up on Toyota Key Fob Not Working After Battery Change.
Questions answered only with the facts above
Does the swap program the car?
No. A battery-only swap does not require programming.
How many cells go in?
One, in almost every Toyota fob. Do not stack a second coin.
What confirms the new cell?
Lock and unlock once from outside the car.