Event Data Recorder (EDR)
Definition
An onboard module that records pre-crash vehicle kinematics (speed, throttle, brake, steering) in the seconds before airbag deployment; governed by SAE J1698 and NHTSA 49 CFR Part 563 in the US, UN Regulation 160 in Europe.
- Data focus
- Vehicle kinematics: speed, throttle, brake, steering angle in the pre-crash window
- Storage method
- Rolling buffer, continuously overwritten until crash trigger activates and saves the data
- Primary integration
- Usually integrated into the airbag control module as part of the vehicle's safety system
Common questions
What does an EDR actually record in a vehicle?+
An EDR captures pre-crash vehicle data like speed, throttle position, and brake status in the seconds before a crash occurs. It stores this information as a rolling buffer until a crash is detected, at which point it saves the data for analysis.
Where is the EDR located in a vehicle?+
The EDR is usually integrated into the airbag control module, so it sits with the vehicle's safety systems rather than as a separate standalone device.
Are there standards that govern EDR data collection?+
Yes. In the US, EDR recording is governed by SAE J1698 and NHTSA 49 CFR Part 563. Europe uses UN Regulation 160. These standards define what data must be recorded and how it is stored.
Related terms
- 49 CFR Part 563
- The NHTSA federal regulation requiring standardised EDR data elements, minimum accuracy specifications, and data durability requirements for passenger vehicles and light trucks...
- CDR Tool
- The Bosch Crash Data Retrieval tool: the industry-standard hardware-software system used to interface with automotive EDR modules via the OBD diagnostic port...
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- Delta-V
- The change in vehicle velocity during the crash event, recorded by the EDR as a time-history. It is the integral of the...
- Energy-Equivalent Speed (EES / Delta-V)
- The SAE J2080 metric quantifying the kinetic energy absorbed by vehicle crush deformation, expressed as the speed change equivalent; used in the...
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- In the absence of external horizontal impulses, the total linear momentum of a two-vehicle collision system (sum of mass times velocity for...
Explained in these topics
- Accident Reconstruction Physics: Velocity, Momentum and Skid MarksAn onboard module that records pre-crash vehicle kinematics (speed, throttle, brake, steering) in the seconds before airbag deployment; governed by SAE J1698 a...
- Event Data Recorders and Black-Box AnalysisA data storage device, usually integrated into the airbag control module, that continuously records a rolling buffer of vehicle operating parameters and saves...