Code EFUSE_w142 was reported by the “Electronic fuse” controller in the car. The letter “w” in the middle places it among entries of the warning type.
The electronic fuse in the 12 V circuit. It protects the supply to key consumers and watches the 12 V battery's temperature and voltage. These codes often appear alongside 12 V battery problems.
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 power steering can only be disabled due to the present of "E-fuse self-tests" upon vehicle wake-up. If either the Electric Power Assist Steering (EPAS) primary or EPAS secondary fault at wake-up, there will be no assistance from the start. Sleeping and waking the vehicle will force a re-test, which will pass the next time if the conditions that caused the initial failure are not present.
If the failure occurred during the drive itself, it is less likely to be E-fuse related. Once driving is underway with a working EPAS, the E-fuse software state is locked out for safety reasons and only the hardware sensing can make it trip. Both the EPAS circuits would have needed to trip their E-fuse during the journey for this to be the case.?
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.