Did your Tesla just welcome you with the message: “BMS_u031 Battery Fuse Requires Replacement Soon – OK to drive, schedule service”?
Don’t worry, here is why and what to do next.
Why has the “Battery Fuse Requires Replacement Soon” appeared in the first place?
The short version: the most probable reason why your Tesla is showing this error message is that this particular generation of HV battery pyro fuse has a tiny internal battery with a limited life span (about 7 years so chances are that if you’re getting this message in 2023/2024, your Tesla is probably a 2016-2017-2018 model) and based on the date, Tesla has calculated that yours is on it’s last 6 months stretch.
The longer version: the error message “battery fuse requires replacement soon” in a Tesla Model vehicle indicates that the vehicle’s battery management system has detected an issue with the HV battery pyro fuse. In Tesla vehicles, the battery pack is a crucial component, and the battery fuse is an essential safety feature. Here’s what this message generally means:
- Battery Fuse Function: The battery fuse in a Tesla acts as a safety device. It is designed to protect the battery pack and the vehicle’s electrical system from overcurrent conditions. If the current flowing through the battery exceeds a safe level, the fuse will blow to prevent damage to the battery and other components.
- Fault Detection: The error message suggests that the vehicle’s diagnostic system has detected a potential fault with the fuse. It may not have failed yet, but it could be close to its end of life or showing signs of wear or damage.
- Urgency of Replacement: While the message indicates a need for replacement soon, it is usually advisable to address such issues promptly. A failing or compromised battery fuse can lead to more significant problems, including potential damage to the battery pack or electrical system, and may also pose a safety risk.
What to do about it?
Replacing the HV battery pyro fuse in a Tesla is typically not a DIY task due to the complexities and safety risks associated with Tesla’s (and any EV) high-voltage systems. As the message in the app suggest, schedule a service appointment with a Tesla service center to have it replaced with a self-powered hybrid pyro fuse which should last a lot longer.
What is the cost to fix it?
While some Tesla owners got charged $300-$700 historically, it now appears that it is covered under the warranty and Tesla should exchange it for free (thecarstuff.com has reached to Tesla for statement on this and are yet to hear back at the time of publication).
Will it happen again?
No, it should not happen again as Tesla is swapping the old fuse models with a new HV ones that should last virtually forever.
