Code DI_a223 was reported by the “Drive inverter” controller in the car. The letter “a” in the middle places it among entries of the alert type.
The Drive Inverter — the power electronics that drive the motor. Codes from here show up as reduced power, a message about limited acceleration or, in worse cases, an inability to drive. Temperature codes are common too: the inverter protects itself under sustained load.
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.
Drive Inverter Warning: Traction control (TC) is disabled
This alert sets any time traction control is not available. This is almost always due to the system being faulted. To diagnose the cause of the fault, check this alert's payload to identify which inputs are in a degraded state.
Steps to find cause:
1) If velocityEstimatorState is degraded, check other DI alert for velocityEstimatorState to find the root cause. If velocityEstimatorState is normal:
2) If btcTargetState or ptcTargetState are degraded, check for CAN bus issues (these signals come from ESP) or sensor issues with ESP (check associated ESP alerts). If target states are normal:
3) If addState is degraded, check for other DI alerts about ADD. If slaveADDState is degraded, check for DIS alerts about ADD and check for other DI alerts indicating CAN communication issues with DIS.
This alert will clear on the drive cycle after traction control is re-enabled or un-faulted.
Traction control is not available. The vehicle should be driven with extreme caution.
Drive Inverter Warning: VCFRONT (Front Vehicle Controller) node is MIA on CAN for one or multiple messages
Drive Inverter Warning: EPB did not apply in standstill state
Drive Inverter User Alert: Rear Motor Mode selected by user
Drive Inverter Warning: EPAS (Steering Assist) node is MIA on CAN for one or multiple messages
Drive Inverter Warning: iBooster (Brake Assist) node is MIA on CAN for one or multiple messages
Drive Inverter User Alert: Brake stand active
Drive Inverter Warning: Stability control (VDC) is disabled
This alert sets any time stability control is not available. This is almost always due to the system being faulted. To diagnose the cause of the fault, check DI alerts set immediately prior to this alert. Also ensure the vehicle is on consistent software with no software version mismatch alerts.
This alert will clear on the drive cycle after stability control is re-enabled or un-faulted.
Drive Inverter User Alert: Vehicle Hold release required
Drive Inverter Warning: Wheel slip signal error
VCFRONT_driverIsLeaving == TRUE && Gear != P
VCFRONT_driverIsLeaving == FALSE
Drive Inverter Warning: Rear wheel speed signal error
Drive Inverter Warning: Accel 5V Supply out of bounds
Drive Inverter Warning: Brake pedal sensor bad
Drive Inverter Warning: Longitudinal acceleration or roll rate error
Drive Inverter Warning: High thread execution time
Drive Inverter Warning: Report of Driver Brake Apply for false-detection diagnostic
Drive Inverter User Alert: Cannot shift gears - Vehicle speed is too high
User attempts to shift above allowed speed limit
User cannot shift gears while speed is too high
Drive Inverter Warning: Suspected implausible input signal, close to faulting
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.