Code BMS_f107 was reported by the “Battery management (BMS)” controller in the car. The letter “f” in the middle places it among entries of the fault type.
The Battery Management System — the brain of the high-voltage battery. It watches individual cell voltages, temperature, isolation resistance and the permitted power output. On a used car this is the most closely watched group of codes, because battery health shows up here. Codes about isolation or cell instability are among those worth having checked promptly.
The more serious level. The affected component has shut down or is running in limp mode. These codes belong in a service centre.
This is how the fault is named inside the car's firmware. For codes without a description it is the most precise clue there is — the name itself says what the event is about.
The text below comes from Tesla's technical documentation. We leave it in the original English so that translation cannot shift its meaning.
A high voltage (HV) battery cell voltage sensor error is detected. There are three reasons for this alert to be reported by the Battery Management System (BMS):BMS_a107_errorType = BMS_A107_MODULEBRICK_MISMATCHThis alerts means that the voltage of the module differs by more than 35mV from the sum of the brick voltages of that module.BMS_a107_errorType = BMS_A107_TVSH_BLEEDV_LOWThis alert type means that the bleed resistor is turned on for that brick, but the voltage is too low (likely due to a stuck bleed resistor).BMS_a107_errorType = BMS_A107_TVSH_IMP_HIGH This alert type is the most common. The system has detected a high impedance on the sensor harness from the Battery Monitoring Board (BMB) to the bricks / module. It means that the measurements from that BMB cannot be trusted.
Copy it exactly, letter and number included. Photographing the screen is safest — codes often differ by a single digit, and mixing them up leads somewhere else entirely.
Some codes clear after a screen restart or after the car sits locked for a few hours. If the code does not come back, it was usually a one-off glitch.
A one-off entry and a code that appears after every drive are two different things. It helps a service centre enormously if you know exactly when it shows up.
With airbags, brakes, steering and high voltage there is no point waiting it out. With the other groups you can watch and see whether the code returns at all.
Error codes are only part of the picture. For cars on TesList you also see battery health pulled straight from the vehicle, plus a price calculator that works out from current listings what a given car is actually worth today.