Event Data Recorder in a Car Accident: What Families Should Know

The Event Data Recorder sitting inside your loved one's wrecked car may contain the single most important piece of evidence in a wrongful death case — and it can be permanently destroyed within days if no one acts to preserve it.

What the EDR Records

Many newer passenger vehicles have an EDR, often built into the airbag control module, but federal law does not require every vehicle to include one. Under 49 CFR Part 563, a vehicle equipped with an EDR must meet federal recording standards. When a qualifying trigger event occurs, the EDR can capture data from the seconds surrounding the crash, including:

• Vehicle speed in the five seconds before impact
• Brake pedal application (on or off)
• Accelerator pedal position and throttle percentage
• Steering wheel angle
• Engine RPM
• Seatbelt buckle status for driver and front passenger
• Airbag deployment timing (measured in milliseconds)
• Delta-V — the precise change in velocity during the collision itself

This is not dashcam footage. It is machine-generated data about the equipped vehicle, which can include speed, braking, and seatbelt status. It does not by itself show exactly how a collision happened, and not every vehicle has an EDR. In a disputed-liability wrongful death case, the data can help investigators assess what happened.

How EDR Data Gets Destroyed

The data is stored in a short loop — roughly five seconds of pre-impact information and fractions of a second post-impact. It does not record continuously. Once captured, the data is retained in the module's memory, but it is vulnerable in several ways:

Ignition cycling. If the vehicle's ignition is turned on and off repeatedly — approximately 250 cycles — the crash data can be overwritten. Tow yard employees, insurance adjusters, or anyone with access to the vehicle's keys can trigger this inadvertently.

Salvage and crushing. Insurance companies routinely push families to sign salvage releases so the wrecked vehicle can be auctioned or crushed. Once the vehicle is destroyed, the physical EDR module is gone permanently.

Electrical damage. In severe collisions, the vehicle's electrical system may be compromised. If the OBD-II port is damaged, extracting the data requires physically removing the airbag control module and connecting to it directly — a procedure that requires specialized hardware.

How to Get the Data

EDR extraction requires a Crash Data Retrieval (CDR) system — proprietary hardware and software sold by Bosch. A certified technician connects to the vehicle's OBD-II diagnostic port (or directly to the removed airbag module) and downloads the stored crash data into a standardized report.

Under federal and state privacy laws, EDR data is the private property of the vehicle owner or lessee. To download it legally, you need one of three things:

1. Written consent from the vehicle owner or their estate representative
2. A court order or subpoena issued during civil litigation
3. A search warrant obtained by law enforcement during a criminal investigation

If your loved one was the vehicle owner, the estate representative (executor or administrator) can authorize the download. If the other driver's vehicle contains the relevant data, your attorney will need to subpoena it or obtain a court order.

The Spoliation Letter

The most urgent step is preventing the data from being destroyed before anyone can extract it. Your attorney should send a formal spoliation letter — a legal preservation demand — within the first days after the crash. The letter goes to:

• The tow yard or impound facility holding the vehicle
• The at-fault driver's insurance carrier
• Any commercial fleet owner if a truck or company vehicle was involved
• The at-fault driver directly

The letter puts parties on notice that litigation is anticipated and that evidence may need to be preserved. A court may impose sanctions if evidence that should have been preserved is destroyed, including an adverse inference instruction in some cases.

For the full evidence-preservation timeline, including a spoliation letter checklist and EDR download coordination steps, the After a Car Accident Death guide covers the process from crash scene through litigation.