I-Key System Fault and Brake Issue

My Nissan Leaf Forum

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New member
Sep 21, 2023
Good Afternoon. About 4 days ago I got in the car without my keys and on the dashboard was an alert that said "I-Key system fault." I grabbed my keys out of my other car and turned my Leaf on. I googled the message and it said that I most likely needed to change the battery in my key fob. This was strange to me since I didn't even have my keys with me when the message was up. Fast forward a few days and the message sometimes is there when I turn the car on, sometimes not, and usually goes away after a few minutes. I called the dealership, and they told me to replace the batteries in my key fob and that was that. Now today, I turned the car on and put it in reverse and it was like my brakes were not working. I looked at the dash and there was an exclamation point inside a circle and the word "brake" was illuminated. What could this be? The dealership made it sound like their EV mechanic is either not there or won't be able to get to my car anytime soon. I'm afraid to drive it right now. It's a 2015 with 98k miles.
A weak 12V battery can cause many odd issues. I'd replace the battery in your FOB(s) and also check the condition/age of the 12V battery.

It could be something else but start with the easy stuff first.