Aygo Key Battery Low

Sounds like the key fob battery is the likely culprit. The error is probably from the communication failing due to low power. I'd swap the battery first. Is the warning light always on, or does it come and go?

Thanks! The warning light is always on when the ignition is on, so it seems like a constant low battery. Is there a specific battery I should use for the Aygo key fob? Can I use a generic one, or should I get an original from Toyota?

Since the warning is constant, a new battery should fix it. A generic might work, but voltage differences can mess with the key's electronics. To be safe, get the OEM battery from Toyota. If it still has issues after that, you'll need a workshop to diagnose it.

Thanks for the help! I got an original battery from Toyota, cost me 37€. Replacing it fixed everything. Keyless entry works, and the error is gone!