These instructions apply to the Hyundai i20 Mk2 (GB) 2014-2020. For other models, please choose your vehicle here.
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If the remote on your Hyundai i20 Mk2 (GB, 2014–2020) only works from up close, or has stopped locking the car altogether, the fob’s coin battery is almost always the cause — and replacing it is a two-minute job you can do at home. This guide covers swapping the key fob battery and explains what you can and cannot do yourself when it comes to a lost or extra key.
First, Rule Out the Battery
A weak fob battery is the number one reason an i20 remote becomes unreliable — short range, needing several presses, or no response. Before assuming anything more serious, fit a fresh cell. Most i20 Mk2 fobs use a CR2032 coin cell.
Replacing the Fob Battery
- If your fob has a fold-out mechanical key, release and remove it — this usually exposes the seam of the case.
- Insert a small flat screwdriver (wrapped in tape to avoid scratches) into the seam and gently separate the two halves of the case. Do not use excessive force.
- Lift out the old CR2032 cell, taking care not to touch the contacts, and not with wet hands.
- Fit the new cell with the positive (+) side facing upwards (the same way the old one sat).
- Clip the case back together and refit the mechanical key blade.
- Test that the remote locks and unlocks the car. The range should be back to normal.
After a battery change the remote keeps its programming — you do not need to re-pair it.
Lost Key or Adding a Spare — What You Can’t Do at Home
Unlike some older cars, the i20 Mk2 cannot have a remote programmed without a diagnostic tool. If a key is lost or you want to add a spare, a replacement must be ordered and coded by a Hyundai dealer or an auto-locksmith with the right equipment — there is no key-and-door sequence that pairs a new fob. So the home job is limited to renewing the battery in a fob that already works.
If a Fresh Battery Doesn’t Fix It
- Check the cell orientation and contacts — a cell fitted upside down or dirty contacts will give no response.
- Try the mechanical key in the driver’s door to get in, and the start button against the fob (many i20s let you start by holding the fob against the button if its battery is flat).
- Still nothing from either fob? The receiver or a body-control fault may be involved — the car can store a code you can look up on autodtcs.com before booking a diagnosis.
Tools and Parts
- A fresh CR2032 coin cell.
- A small flat-blade screwdriver (taped) to split the case.
Frequently Asked Questions
What battery does the i20 Mk2 key fob take?
Most use a CR2032 coin cell. Check the old one when you open the fob to confirm.
Do I need to reprogram the remote after changing the battery?
No — the programming is retained. Just fit the new CR2032 the correct way round and test it.
Can I program a new i20 key myself?
No — the i20 Mk2 requires a diagnostic tool to pair a remote, so a new or replacement key must be coded by a Hyundai dealer or a locksmith.
My fob battery is flat — how do I start the car?
Use the mechanical key to unlock the door, then hold the fob against the start button (or the marked spot) and press — the car can read the transponder directly to let you start.
If the remote stopped working after a battery disconnection, see our Hyundai i20 Mk2 battery disconnect/reconnect guide.
Disclaimer: The information on this page is provided for general guidance only. Always follow your official service manual and safety precautions when working on your vehicle. We are not responsible for errors, omissions, or any damage resulting from the use of this information.
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