Code TAS_a225 was reported by the “Air suspension” controller in the car. The letter “a” in the middle places it among entries of the alert type.
Tesla Air Suspension — the air chassis: compressor, valves, ride height sensors. These codes show up as the car being unable to raise or level the body, or reporting a loss of pressure. On Model S and X this is a common age-related fault.
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.
Gallery pressure was measured to be higher than expected under any operating condition.
Front axle has been measured to be lower than any reasonable height.
Front axle has been measured to be lower than any reasonable height for an extended period.
Front axle has been measured to be not be lower than any reasonable height for an extended period.
Debug information for 100ms task errors. Set along with TaskSchedulerError.
Front right air valve detected short circuit.
Front right air valve output shorted to ground or battery voltage.
One or more CAN messages from GTW are not being received by the ECU.
One or more CAN messages from GTW are not being received by the ECU (missing, bad RX rate, or invalid checksum/counter).
Successful reception of all RXd CAN messages from GTW.
Air suspension functionality may be reduced. Air suspension may not be able to recover from corrected faults.
Debug information for 1000ms task errors. Set along with TaskSchedulerError.
Rear right air valve detected open circuit.
Rear right air valve commanded on but no electrical current measured.
Front left air valve has reached its duty cycle (on time) limit.
Front left air valve has dropped below its duty cycle (on time) limit, plus some hysteresis.
Air suspension leveling will be temporarily disabled until front left air valve duty cycle drops.
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.