Code EPAS_d037 was reported by the “Electric power steering” controller in the car. The letter “d” in the middle places it among entries of the diagnostic entry type.
Electric power-assisted steering. These codes show up as a heavy steering wheel, a message about reduced assist, or Autosteer switching off. The car still steers, just with far more effort.
A service record that is not shown to the driver. Only a technician sees it in diagnostics.
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.
Motor Driver: The Comparison of the Voltage Length Angle has failed.
The deviation between the voltage vectors of the Pulse Width Modulation (PWM) output and the Voltage phasor, which is using the synchronous generated voltage, phase current, and the Motor model, is calculated as too large. The length difference between the voltage vector (from which the Emf calculates the measured currents), the motor model, and the voltage vector extending through the terminal voltage (PWM) is too large. The FOR has to be active, the rotor speed less than 6000rpm, and ECU-Home must be passed 100ms.
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.