Code EPAS_d029 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.
The core self-test (Library from NEC) has failed.
Once developed by the processor, the test routine is run. The registry hardware and machine instructions are called. The test routine runs every 10 ms. The return value of this test routine are 2 fixed values being compared, depending on the predetermined starting value. If the return value of the test routine from the fixed value occurs, the fault entry triggers.
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.