DI family
DI_a123_trailAssistUnavailable
Trail Assist unavailable
What does the DI_a123_trailAssistUnavailable alert mean?
The drive interface (DI) electronic control unit (ECU) detects that the Trail Assist feature is unavailable.
What you'll see in your Tesla
- Trail Assist unavailable
- Not Available
What triggers it
One of Trail Assist's unavailable reasons is active when requesting to activate.
When it clears
The DI ECU detects that the condition preventing Trail Assist is no longer present.
Potential impact
The DI may not be able to provide crawl or hill descent torque when Trail Assist is selected on UI.
Affected models
Cybertruck
Track your Tesla's alerts automatically
Alerts like this reach MyTeslaMate through your car's Tesla telemetry API. MyTeslaMate logs every alert your Tesla reports and turns it into readable history and real-time notifications — hosted TeslaMate with no server to run.