These instructions apply to the Honda Civic Mk10 (FK) 2016-2021. For other models, please choose your vehicle here.
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If the remote on your Honda Civic Mk10 (FK, 2016–2021) is getting weak — short range, fussy keyless entry, or a “key battery low” message — the coin cell needs renewing. The Civic smart key takes a CR1620 (a smaller cell than many cars use, so check before you buy) and opens with the emergency key inside.
What You’ll Need
- A fresh CR1620 3 V lithium coin cell — not the more common CR2032.
- The emergency key that slides out of the fob, plus a small flat screwdriver.
How to Replace the Civic Mk10 Key Battery
- Slide out the emergency key — push the release latch and withdraw it.
- Use the slot the key leaves (or a small screwdriver in the seam) to split the case and remove the cover.
- Lift out the old CR1620, noting which way up it sits.
- Fit the new cell the same way, by the edges.
- Click the case together and slide the emergency key home.
- Test lock/unlock and keyless entry from a normal distance.
Does It Need Programming?
No — the swap doesn’t affect the key’s pairing, so it works straight away. A lost or extra smart key can only be ordered and coded by a Honda dealer.
If It Still Won’t Respond
Re-open the fob, check it’s a CR1620 the right way up and the contacts are clean. If keyless entry is slow, hold the fob against the start button to start, then it re-syncs.
Frequently Asked Questions
What battery does the Honda Civic Mk10 key take?
A CR1620 3 V lithium coin cell — smaller than the CR2032 many cars use, so double-check.
Will the car start with a flat key battery?
Yes — hold the smart key against the start button to start on the backup transponder; the emergency key unlocks the driver’s door.
Which way up does the cell go?
Match the orientation of the cell you removed.
Can I program a spare key myself?
No — Honda key coding needs the dealer system. Only the battery swap is DIY.
To clear a service reminder after maintenance, see our Civic Mk10 service reset guide. For warning lights, look up the code on autodtcs.com.
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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