A Honda key fob that quits the moment you fit a new battery was almost always working before the shell came apart. The new cell did not erase the fob. Something about the way it went back together did.
The battery, stated plainly
| What this page covers | honda key fob not working after battery change |
|---|---|
| Battery to buy | The same number that came out |
| Fob you are likely holding | The shell you just opened |
| Cell type | 3-volt lithium coin cell. Do not use a rechargeable LIR cell. |
| Programming after the swap | Not required when you only change the battery. |
The first check is orientation. A coin cell has a smooth plus face and a smaller minus face. The shell has a molded mark. If you followed a photo of a different generation, you may have the right cell in backward. It will look seated. It will do nothing.
The second check is the part number. A CR2025 in a CR2032 cup, or a CR2032 forced into a CR1616 remote, produces exactly this symptom. So does a rechargeable LIR2032. Take the cell back out and read it under a lamp.
The third check is the contact finger and the shell. If the finger is bent flat, it no longer presses. If the two halves of a smart fob are not fully clicked, the button mat does not line up and the case can short the cell. Look for a gap along the seam. Squeeze again until it clicks all the way around. Put the emergency key back. The key is not decorative. On some shells it also keeps the halves aligned.
This happens in every market because the shells are plastic and the cells are round. A cold garage makes your hands clumsy. It does not create a new electronic fault. Do not pay for programming until a correctly fitted, correct-size, name-brand cell has failed a curb test.
Changing the cell
Open it again. Photograph the cup. Fit the cell to the molded marks. Close the shell completely. Test lock and unlock outside. If that fails, try a second new cell from a different package in case the first was flat on the shelf. Only then think about the fob itself.
Related guides
- Honda Key Fob Battery Polarity
- How to Replace a Honda Key Fob Battery
- Reprogram a Honda Key Fob After a Battery Change?
- Honda Key Fob Battery In Backwards
Questions people ask
Why did my Honda fob stop working after I changed the battery?
The cell is commonly backward, the wrong thickness, or the shell is not fully latched. Programming was not erased.
Should I reprogram it?
No, not for a battery swap. Reprogram only if this is a different fob the car has never learned.
The buttons click but the car ignores them. Now what?
Check polarity and that both contacts touch the cell. Then hold the fob on the start button. If the car starts that way, the immobilizer is fine and the transmitter cell circuit is the problem.
Honda is a trademark of Honda Motor Co., Ltd. Honda Key Fob Battery is an independent guide and is not affiliated with, endorsed by, or sponsored by Honda. The code printed on the cell already in your fob overrides any chart. A fob bought later, or a car sold in another country, can use a different shell.