DI family
DI_a238_secondaryCollisionMitigationActive
Collision detected
What does the DI_a238_secondaryCollisionMitigationActive alert mean?
The Electronic Stability Program (ESP) electronic control unit (ECU) is actuating the brakes to prevent a secondary collision.
What you'll see in your Tesla
- Collision detected
- Brakes applied and acceleration disabled
What triggers it
The ESP reports secondary collision mitigation is active.
When it clears
The vehicle comes to a complete stop or the driver overrides the ESP by using the accelerator pedal.
Potential impact
The ESP ECU may engage the brakes and the DI will remove accelerating torque.
Affected models
Cybertruck
Model 3 2017-2023
Model 3 2024+
Model S 2021+
Model X 2021+
Model Y
Model Y 2025+
Semitruck
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.