Code DI_w127 was reported by the “Drive inverter” controller in the car. The letter “w” in the middle places it among entries of the warning type.
The Drive Inverter — the power electronics that drive the motor. Codes from here show up as reduced power, a message about limited acceleration or, in worse cases, an inability to drive. Temperature codes are common too: the inverter protects itself under sustained load.
The car is flagging that something is not right. Driving is usually still possible, but some function may be limited.
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.
The Drive Inverter has detected that the vehicle has begun a Graceful Power Off.
The motor controller will assert this condition whenever any of the following alerts or controller area network (CAN) signals are present:
No Battery Power (any amount of time)GTW_notEnough12VforDrive (any amount of time)
This alert will also trigger whenever any of the temperatures below exceed their Graceful Power Off thresholds for the specified time:Outlet fluid (2 seconds)Internal ambient (2 seconds)Any of the Isolated Gate Bipolar Transistor (IGBT) heatsinks (3 seconds)Stator (2 seconds)Fluid delta T too positive (2 seconds)
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.