🚀 Immediate Steps to Take

  1. Use the hidden mechanical key inside the fob to unlock the driver’s door (there’s a small release on the fob to slide the key out; the key cylinder is typically behind a small cover on the driver’s door handle).
  2. Start the Civic using the emergency start method: hold the fob right next to the START/STOP button and press the button (the car can read the fob’s transponder even with a dead battery).
  3. Replace the key fob battery with the correct coin cell (commonly CR2032 on many Honda smart fobs, but confirm by opening the fob or checking your owner’s manual) and test lock/unlock and remote start (if equipped).

Your Options

DIY: Replace the key fob battery (coin cell)

Cost: $5-$15 Time: Varies

This is the most common solution for a dead key fob battery on a 2024 Honda Civic. You open the fob case, swap in a new coin-cell battery (match the type printed on the old battery), and reassemble. No programming is typically needed for a simple battery replacement.

âś“ Pros:
  • Fastest and cheapest fix in most cases
  • No special tools or programming usually required
  • You can do it anywhere (home, parking lot) with the right battery
âś— Cons:
  • It’s possible to crack the fob shell or damage clips if pried incorrectly
  • If the issue isn’t the battery (water damage, worn buttons), this won’t solve it

Use the backup entry + emergency start method (temporary workaround)

Cost: $0-$10 Time: Varies

If you can’t replace the battery immediately, you can still access and drive your Civic. Use the mechanical key to unlock the door, then hold the fob against/next to the START/STOP button and press to start. This gets you mobile until you can install a new battery.

âś“ Pros:
  • Gets you back in and driving right away
  • No parts required to start the car
  • Useful even if the fob battery dies unexpectedly
âś— Cons:
  • Alarm may sound briefly when unlocking manually (varies by settings/model)
  • Doesn’t restore remote lock/unlock range until the battery is replaced

Have the battery replaced/checked by a professional (dealer or independent locksmith)

Cost: $20-$80 Time: Varies

If you’d rather not open the fob—or you want the fob tested for weak contacts, damage, or low-voltage issues—an automotive locksmith or dealership can replace the battery and confirm the fob is transmitting properly. This is also a good step if the battery swap didn’t fix the problem.

âś“ Pros:
  • Reduces risk of damaging the fob case or seals
  • Can diagnose whether the issue is the fob vs. the vehicle
  • Helpful if you have only one working fob and want to avoid mistakes
âś— Cons:
  • Costs more than DIY
  • May require travel/wait time

Replace the key fob (if battery replacement doesn’t help)

Cost: $150-$250 Time: Varies

If a new battery doesn’t restore function, the fob may have internal damage (water intrusion, broken solder joints, worn buttons) or be failing electronically. A replacement fob will need to be matched/programmed to your 2024 Civic. Keep in mind pricing varies widely depending on whether you buy OEM vs. aftermarket and whether cutting/programming is included.

âś“ Pros:
  • Restores reliability when the original fob is failing
  • Often the only fix for water damage or internal failure
  • Good opportunity to add a spare fob
âś— Cons:
  • Most expensive option
  • Requires programming and (if needed) cutting the emergency key blade

⚠️ What to Avoid

✕ Avoid forcing the fob open with a large screwdriver or knife—cracked housings and broken clips are common when prying aggressively.

âś• Avoid buying the wrong coin-cell battery type or installing it upside down; always match the number printed on the original battery and confirm polarity before closing the fob.

✕ Avoid paying for “reprogramming” if the only issue is a dead battery—battery replacement typically does not require reprogramming on a 2024 Honda Civic.

Frequently Asked Questions

Can I start my 2024 Honda Civic if the key fob battery is dead?

Yes. Use the mechanical key to get inside if needed, then hold the fob right next to the START/STOP button and press the button. The car can read the fob’s transponder at close range even when the fob battery is dead.

What battery does a 2024 Honda Civic key fob use?

Many Honda smart key fobs use a CR2032 coin-cell battery, but it can vary by fob style/trim. The safest approach is to open the fob and match the battery number printed on the existing coin cell or confirm in your owner’s manual.

Do I need to reprogram the key fob after replacing the battery?

Typically no. A simple battery swap should not erase programming on a 2024 Honda Civic smart key. If the fob still doesn’t work after replacement, double-check battery orientation, contact alignment, and consider fob damage or interference.

Need Detailed Information?

Get vehicle-specific key fob compatibility, part numbers, and a complete price comparison for your 2024 Honda Civic.

View Civic Key Fob Guide →

Last updated: 2026-01-04