Code VCLEFT_a312 was reported by the “Left vehicle controller” controller in the car. The letter “a” in the middle places it among entries of the alert type.
Vehicle Controller Left — the left body controller. It runs the left-hand doors, windows, mirrors, seats and their heating.
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.
A fault has been detected with the left body-side tail light.
The light is plugged in, draws current when on, and its efuse is not tripped.
The left body-side tail light may not be working.
Electronic Parking Brake Monitor measured more current than is required for Electronic Parking Brake to remain in DYNAMIC_APPLYING.
FL ride height sensor detected shorted or otherwise faulty. n/a to North American or Air Suspension eqiupped vehicles.
FL ride height sensor input pin shorted; input signal frequency above 840 Hz or below 760 Hz; input duty cycle above 87.5% or below 12.5%; input duty cycle changing too quickly (3300% / sec)
Proper connection of a working FL ride height sensor.
Electronic Parking Brake Monitor's and Electronic Parking Brake's state have been mismatched for too long a time.
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.