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Dead 2024 Hyundai Tucson Key Fob Battery? How to Start, Unlock, and Replace It Fast

Key fob battery is dead or dying

🚀 Immediate Steps to Take

  1. Try the backup start method: with the fob in the vehicle, use the car’s emergency fob-detection procedure (often holding the fob close to the START/STOP button area) and press the brake + START/STOP.
  2. Use the hidden mechanical key to unlock the driver door if the buttons don’t respond (remove the mechanical key from the fob and unlock the door manually).
  3. Replace the fob battery with a new, name-brand coin cell (commonly CR2032 for many Hyundai smart fobs—confirm by opening the fob or checking your owner’s manual) and test lock/unlock and remote start (if equipped).

Your Options

DIY battery replacement (most common fix)

Cost: $3-$10 Time: Varies

Open the 2024 Hyundai Tucson smart key fob, note the battery orientation (+/-), and install a fresh coin-cell battery. This typically restores normal lock/unlock and key detection immediately. If it doesn’t, double-check battery orientation and that the fob housing is fully snapped closed.

✓ Pros:
  • Cheapest option
  • Fast—often solved the same day
  • No programming is usually required for a simple battery swap
✗ Cons:
  • Risk of cracking the case if pried incorrectly
  • Using the wrong battery type or low-quality cells can cause repeat failures

Buy a replacement battery locally and have it installed

Cost: $5-$25 Time: Varies

Many retail counters that sell coin-cell batteries can help confirm the correct size and may assist with installation (policies vary). This is useful if you’re unsure whether your Tucson fob uses CR2032 or another coin cell, or you want to avoid damaging the fob housing.

✓ Pros:
  • Quick access to the correct battery
  • Less chance of buying the wrong size
  • Reduces the chance of damaging the fob during opening
✗ Cons:
  • May cost more than DIY
  • Not every location will install or handle customer key fobs

Dealer diagnostic if battery replacement doesn’t fix it

Cost: $0-$200 Time: Varies

If a new battery doesn’t restore operation, the issue may be the fob itself, a damaged battery contact, or a vehicle-side problem (receiver, antenna, or related module). A dealer can verify whether the vehicle is seeing the fob and whether the fob is transmitting properly. This is also a good path if your Tucson is still under warranty and you suspect a defective fob.

✓ Pros:
  • Accurate diagnosis if it’s not just the battery
  • Access to Hyundai-specific testing and service info
  • May be covered if a defect is found under warranty (varies by coverage and cause)
✗ Cons:
  • Appointment and wait time
  • Higher cost if it’s not warranty-related

Replace the key fob (only if the fob is failing)

Cost: $250-$650 Time: Varies

If the fob has been dropped, exposed to water, or has worn-out internal contacts, a battery won’t solve it. Replacing the fob requires obtaining the correct Hyundai-compatible smart key and having it programmed to your 2024 Tucson. This is usually the most expensive route, so it’s best after confirming the battery and contacts are not the issue.

✓ Pros:
  • Solves problems caused by a failing or damaged fob
  • Restores full functionality and reliability
  • Can add a spare if you’re down to one working fob
✗ Cons:
  • Most expensive option
  • Programming/registration is typically required

⚠️ What to Avoid

✕ Avoid paying for a full key replacement before you’ve confirmed the correct coin-cell battery type and orientation—battery issues are far more common than fob failure.

✕ Avoid ultra-cheap or old-stock coin cells; weak batteries can cause short range, intermittent unlocking, and ‘Key Not Detected’ messages even when “new.”

✕ Avoid prying the fob aggressively with sharp metal tools; it’s easy to crack the shell or damage the internal clips and battery contacts.

⚠️ Common Mistakes to Avoid

  • Using wrong battery type
  • Damaging case during opening
  • Not resetting after replacement
  • Buying expensive batteries

Frequently Asked Questions

Can I start my 2024 Hyundai Tucson if the key fob battery is dead?

Usually, yes. Your Tucson has an emergency method that allows the car to detect the fob at close range even with a dead battery. Use the mechanical key to get in if needed, then follow the owner’s manual procedure—commonly holding the fob very close to the START/STOP button area while pressing the brake and START/STOP.

What battery does a 2024 Hyundai Tucson key fob use?

Many Hyundai smart key fobs commonly use a CR2032 coin-cell, but it can vary by fob style/trim and market. The most reliable way is to open the fob and read the battery code printed on the existing coin cell, or confirm in your owner’s manual.

After replacing the battery, my Tucson still says ‘Key Not Detected.’ What should I do?

First, confirm the battery is brand-new, the correct type, and installed with the correct polarity, and that the fob case is fully snapped shut. If it still fails, try your spare fob (if available) and rule out interference (other keys, electronics, or a dead 12V vehicle battery). If the issue persists, the fob may be damaged or the vehicle’s receiver system may need diagnosis.

Related Information

Need Detailed Information?

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

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Last updated: 2026-01-04