Code DI_a232 was reported by the “Drive inverter” controller in the car. The letter “a” in the middle places it among entries of the alert 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 most common type. The car logged the event and may have shown it on the screen. The range is wide — from something trivial that clears itself to something that needs attention.
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.
Drive Inverter Warning: Velocity estimate accuracy is degraded
Drive Inverter Warning: Rear drive unit disabled
Fault detected in the rear drive unit
Fault in rear drive unit is no longer present
Unable to produce any torque or power on the rear wheels
Drive Inverter Warning: Wheel rotation signal error
Drive Inverter Warning: PTC CAN node is missing.
Drive Inverter Fault: Cruise faulted
Drive Inverter User Alert: Track Mode Active
Drive Inverter Warning: Vehicle Hold faulted
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.