Renault Master key battery low warning

I had a similar problem with my Master. The key battery low warning came on intermittently, then the keyless entry became unreliable. Eventually, it stopped working altogether. Have you tried using the spare key to see if the problem persists? It could rule out a deeper issue with the vehicle's receiver.

Good point about the spare key. I'll give that a try. If the spare works fine, does that definitely point to a faulty battery in the original key, or could there still be something else at play?

In my case, the spare key worked perfectly. Since the spare worked fine, replacing the battery in the original key fob resolved the issue. If you are unsure or can't replace the battery yourself I would suggest a visit to the workshop.

The spare key worked flawlessly. Replaced the battery in the original fob for 37€, and everything is back to normal. Thanks for pointing me in the right direction!