Dead Key Fob Battery medium urgency

2024 Tesla Model Y Dead Key Fob Battery (US): How to Get Back In and Start

If your 2024 Tesla Model Y key fob suddenly stops unlocking or locking the car, the fob’s coin-cell battery may be dead. The good news: you can usually still get in and drive using your phone key or a backup method while you replace the battery.

Understanding Your Situation

A depleted coin-cell battery inside the Tesla key fob reduces or stops the fob’s Bluetooth/RF signal, so the car can’t detect it reliably. This can cause intermittent unlocking, no response to button presses, or the vehicle not recognizing the fob as a key.

🚀 Immediate Steps to Take

  1. Use Phone Key if available: Open the Tesla app and unlock the car; keep your phone with you to drive (Bluetooth must be on).
  2. Try your backup access method: If you have a key card, use it to unlock (tap at the driver-side B-pillar) and to start (place on the center console card reader area, per on-screen prompt).
  3. Replace the fob battery: Install a new coin-cell battery of the correct type (commonly CR2032 for Tesla fobs), ensuring correct polarity; test lock/unlock and passive entry afterward.

Your Options

Replace the key fob coin-cell battery (DIY)

Cost: $3-$12 Time: Same day

Open the key fob and replace the internal coin-cell battery with a fresh, name-brand cell. Confirm the battery type printed on the old battery before buying, then test the fob near the vehicle.

âś“ Pros:
  • Lowest cost solution
  • Fast fix with minimal downtime
âś— Cons:
  • Requires careful handling to avoid damaging the fob housing
  • Wrong battery type or incorrect polarity can prevent operation

Use Phone Key as primary and keep a key card as backup

Cost: $0-$0 Time: Immediate

If your phone key is set up, you can continue driving without the fob while you replace the battery or decide whether you still need the fob. Keep a charged phone and carry a key card as a reliable backup.

âś“ Pros:
  • No parts needed if already configured
  • Often more convenient than carrying a fob
âś— Cons:
  • Depends on phone battery, Bluetooth, and app access
  • Not helpful if phone key isn’t set up and you don’t have a key card available

Tesla Service / Mobile Service inspection (if battery replacement doesn’t fix it)

Cost: $0-$250+ Time: 1-7 days

If a new battery doesn’t restore normal function, schedule Tesla Service to check the fob, pairing, and vehicle receiver issues. This may include re-pairing or replacing the fob if it has failed.

âś“ Pros:
  • Professional diagnosis if the issue isn’t the battery
  • Can resolve pairing or hardware faults
âś— Cons:
  • May require an appointment wait
  • Potential cost if replacement hardware is needed

⚠️ What to Avoid

✕ Don’t force the fob open with sharp tools that can crack the housing or damage internal clips.

✕ Don’t install a random coin-cell size—match the exact battery type printed on the old battery (commonly CR2032) and confirm polarity.

✕ Don’t assume it’s only the fob if the car is also having phone key issues—low 12V battery, app/Bluetooth problems, or pairing issues can mimic fob failure.

Frequently Asked Questions

Can I drive my 2024 Model Y if the key fob battery is dead?

Yes, if Phone Key is set up you can unlock and drive with your phone. If you have a Tesla key card, you can unlock by tapping it on the driver-side B-pillar and start by placing it on the designated card reader area inside the car as prompted.

What battery does the Tesla key fob use?

Many Tesla key fobs use a CR2032 coin-cell, but you should confirm by checking the battery marking inside your specific fob before purchasing a replacement.

The new battery didn’t fix it—what else could it be?

Common causes include incorrect battery type, reversed polarity, poor battery contact, a damaged fob, or the fob needing to be re-paired. If phone key and key card work but the fob doesn’t, schedule Tesla Service to diagnose the fob and vehicle receiver.

How long should a key fob battery last?

Battery life varies with use and environment, but coin-cell fob batteries often last 1–3 years. Frequent use, extreme temperatures, or a low-quality battery can shorten lifespan.

⏱️ Urgency Note: Low to moderate urgency: You can usually keep driving using Phone Key or a key card, but replace the fob battery soon to avoid being locked out if your phone dies or loses connectivity.

Related Information

Need Detailed Information?

Get vehicle-specific key fob compatibility, part numbers, and a complete price comparison for your 2024 Tesla Model Y.

View Model Y Key Fob Guide →

Last updated: 2026-01-04