Code GTW_w319 was reported by the “Gateway” controller in the car. The letter “w” in the middle places it among entries of the warning type.
The Gateway — the hub through which the car's controllers talk to each other, and the route software updates take. Codes from here often mean some controller has gone quiet on the bus; the real fault is usually in that controller, not the gateway.
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 battery management system (BMS) constantly measures or calculates the resistance across the pack contactors by looking at the voltage difference when the current is stable between the battery side and vehicle side of the power switches.
The current is always fluctuating at the power switches, meaning the measurement is never perfect, and the BMS associates a confidence index to each measurement. The more stable the current and the longer it is stable, the higher the confidence index will be. ?
The Gateway will report this alert and start a log upload when:
The confidence index is on the lower side (but still acceptable) and the power switch (either positive or negative) resistance measurement is above 1.5mohms.
The confidence index is good (more confidence in the measurement) and the power switch (either positive or negative) resistance measurement is above 1.0mohms.
In parallel, the BMS also calculates the contactors stress, which directly relates to the contactors impedance. There cannot be stress without impedance.
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.