Code TAS_a073 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.
On board 5V switched supply is measured to be below 4.5V.
Air suspension leveling will be disabled. Systems with adaptive dampers will no longer drive current to dampers.
Debug information for 10ms task errors. Set along with TaskSchedulerError.
Rear left height sensor disconnected, or signal line from rear left PWM height sensor floating.
Expected PWM signal received from rear left ride height sensor.
Failure of a software assertion.
Auto clears after 10ms of no new assertions.
Reservoir air valve has reached its duty cycle (on time) limit.
Reservoir air valve has dropped below its duty cycle (on time) limit, plus some hysteresis.
Air suspension leveling will be temporarily disabled until reservoir air valve duty cycle drops.
Rear right height sensor disconnected, or signal line from rear right PWM height sensor floating.
Indicates an active connection to the XCP state machine
Exhaust air valve has reached its duty cycle (on time) limit.
Exhaust air valve has dropped below its duty cycle (on time) limit, plus some hysteresis.
Air suspension leveling will be temporarily disabled until exhaust air valve duty cycle drops.
Front axle has been measured to be higher than any reasonable height.
Front axle has been measured to be higher than any reasonable height for an extended period.
Front axle has been measured to be not be higher than any reasonable height for an extended period.
Vehicle may fail to level to correct ride height.
Air suspension failed to adjust to target ride height.
Vehicle may not be at correct ride height.
Reservoir air valve detected open circuit.
Reservoir air valve commanded on but no electrical current measured.
Boost air valve detected open circuit.
Boost air valve commanded on but no electrical current measured.
Air suspension raising will only occur via reservoir or air compressor.
Static vehicle spring leak check detected a spring leak on the front right air spring.
Front right air spring leak was detected with vehicle static.
Sleep cycle, or successful static spring leak check.
Reset can be caused by: Clock Error, Flash Error, Software Reset, Checkstop Reset, Debug Reset
One or more CAN messages from CP are not being received by the ECU.
One or more CAN messages from CP are not being received by the ECU (missing, bad RX rate, or invalid checksum/counter).
Successful reception of all RXd CAN messages from CP.
Air suspension will assume the vehicle is not charging.
Air suspension system is operating under limp home mode 30 restrictions.
The ECU has detected an issue whose severity requires operating under limp home mode 30 restrictions.
Air suspension leveling will be disabled, expect lowering to STANDARD via speed based restrictions on higher heights.
Static vehicle spring leak check detected a spring leak on the front left air spring.
Front left air spring leak was detected with vehicle static.
Signal line from rear left PWM height sensor shorted to ground.
Implausible condition detected on boost air valve circuit.
Implausible condition detected on boost air valve circuit, possibly due to ECU hardware failure.
ECU has requested suspension red warning lamp to be displayed.
ECU has requested suspension red warning lamp to not be displayed.
Red suspension warning lamp will be displayed.
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.