Symptoms
- Fob works sometimes but not others in the same spot
- Problem improves when other keys or phones are moved away
- Fob works fine at home but not near certain buildings or garages
- No issue when fob is isolated on its own
Likely causes
- CommonOther fobs or RFID cards on the same keyringTransit cards, other car fobs, or hotel key cards can interfere with the fob's signal.
- PossibleNearby strong wireless sourcesCertain garages, parking structures, or electronics can create radio interference that blocks weaker fob signals.
- PossibleMetal phone case or wallet blocking signalMetal-backed cases or RFID-blocking wallets can shield the fob if stored together.
- PossibleWeak fob battery making it more susceptibleA borderline battery has less signal strength to overcome any interference.
What to do
- Separate the fob from other keys, cards, and phones and test again in the same spot.
- Replace the fob battery, since a strong signal is more resistant to interference.
- If the problem only happens in a specific garage or building, note that as likely environmental interference rather than a fob fault.
- Try holding the fob directly against the door handle or start button rather than at a distance.
- If you use an RFID-blocking wallet or metal phone case near your keys, keep them separated.
Tools and parts
- Replacement coin-cell battery
Key fob batterySearch: “key fob battery for your car model”
When to call a pro
If interference happens everywhere and a fresh battery doesn't help, a dealer can check the car's receiver for a hardware issue.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.