Code APP_w318 was reported by the “Autopilot — application layer” controller in the car. The letter “w” in the middle places it among entries of the warning type.
The application layer of Autopilot. Drives adaptive cruise control, lane keeping, lane changes and sign recognition. Faults here usually mean an assistance feature switched itself off temporarily — typically due to poor visibility or incomplete camera calibration.
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.
Unexpected physical attribute detected for right repeater camera - no service action needed
Generic debug alert for sending SW assert
Warns if APP fails to receive one or more CAN msgs from VCFRONT on Party Bus
APP fails to receive one or more CAN msgs from VCFRONT on Party Bus
APP starts receiving all CAN msgs from VCFRONT
Some AP features like auto wiper will be impacted
LSS (Lane support system) Abort Diagnostics
Lane keep assist (LKA) or ELK (Emergency lane keep) is de-activated from activated
Cleared on next LKA/ELK activation
Notifaction alert that indicates LSS not keeping vehicle in lane.
Lane keep assist has activated with no hands on detected
Vehicle is encroaching to neighboring lane
Steering adjustments to keep vehicle in lane
Indicates a fault on radar sensor.
Fault reason is specified in alert payload.
A turn indicator fault is preventing lane departure avoidance from activating on one or both sides of the vehicle.
One or more turn signals are faulted
ACC Unavailable - Camera Blind/blocked
info from manualAPP_W222
Sensor exterior needs to be cleaned/replaced if sensor is broken
ACC (Adaptive cruise control) is not available
New right repeater camera calibration values are available
New right repeater camera calibration data is available
New calibration data is available
Will actuate brakes to mitigate collision
Temporary Autosteer Unavailable alert
info from manualAPP_W207
Unavailable reason is in lcUnavailableReason signal
Autopilot features are not available
Indicates DI (Drive Inverter) ECU is mia
One or more of DI messages are missing
Autopilot starts receiving these messages
Media control unit (MCU) ecu is mia
One or more messages specified in the payload are missing
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.