Event Data Retrieval: 4 Problems You Could Face

When the recorders work as intended, an EDR can be the most valuable tool in crash investigations.

By Carla Rodriguez | Nov. 21, 2023 | 4 min. read

What is an EDR tool?

This is one, if not the most useful tools available in crash investigations. Also known as a Crash Data Retrieval, 95% of all vehicles have this technology except for Hyundai and Kia which have their own version of an EDR system. When the recorders work as intended the EDR provides valuable information that can help verify or deny the validity of the crash.

Crash Data Records

So, what information does this high-tech tool give us?

1. Pre-crash data: This section lists pre-crash data records stored on the vehicles event data recorder. It shows the MPH, brake pedal engagement and steering input within 5 seconds before the impact.
2. Seat Belt and Airbag Status: This section lists the restraint system status at the time of the event. It records if and when, the airbag was deployed and the status of the seatbelt buckle. We can see if there were unbuckled passengers or an unbuckled driver.
3. Flags/Loss Indicators: This section flags events for further investigation based on known anti-fraud indicators. For example:

  • Avoidance maneuver: if there is no driver input for brake or steering within 2 seconds of impact
  • Panic stop: rear-end collision where driver brakes just prior to impact, indicating fraud.
  • Pre-damaged vehicle: this is when there is evidence of prior accident damage

4. Diagnostic Scan Data: This section lists any potential recalls, safety ratings or diagnostic trouble codes (DTCs).

What is a Maximum Delta-V?

The Maximum Delta V is the most important piece of information that has to do with the impact of the accident. The Delta-V measures the severity of a traffic collision.

It is important to note that all staged accidents are low speed, low impact. If there is a Delta V lower than 5 MPH, then it is scientifically proven that this cannot hurt someone. Therefore, the vehicle does not record incidents with a severity of less than 5 mph Delta-V.

4 Problems You Could Face

In some cases, the data taken from an EDR is not admissible, due to corruption of the files, failure to record, or damage incurred during a crash. However, if there are two or more vehicles involved and more than one of the vehicles have on-board EDRs, the likelihood of the data being consistent is obviously increased. Here are issues to watch out during an EDR:

1. Not all vehicles are compatible
There are currently three companies that offer EDR retrieval software: Bosch, GIT and Tesla. Click this link to confirm the vehicle you are inspecting is supported by this software.

2. Not all crashes trigger the recorder
Lets put it this way, if there was an airbag deployment then there will likely be data recorded. The system must see a five mile per hour change in velocity or Delta V to record crash related date. But if the person is claiming injuries were sustained with a Delta V under 5 then there is likely something suspicious with this case.

3. Some recorders may be damaged or lose power during a crash

If the vehicles battery and wiring harness have not been damaged, then the data will be extracted using a CDR tool operated by a licensed professional. Use caution when connecting D2M (direct to module) cables and adapters used to connect the CDR tool directly. After a severe crash the vehicles electrical system may be compromised or damaged and the data may not be accessible through the standard DLC connector. That’s a lot of confusing acronyms so make sure you have a knowledgeable investigator to help navigate that.

4. Data corruption:

The most popular EDR software is Bosch. You want to make sure the retrieval and interpretation of the EDR data is done by a properly trained investigator so it can be admitted into court. Its safe to say the raw file is not editable and we only have access to an “image” of the stored data making it mostly immune to image corruption.


Bottom Line

It’s important to note that the use of crash data retrieval should be conducted in accordance with data protection regulations, and requires expertise to ensure accurate analysis and avoid misinterpretation. The Event Data Retrieval tool is engaged anytime a vehicle senses a sudden deceleration such as when a driver jams on the brakes to avoid a collision, the airbag system will wake up and the EDR will start to record data. This data is incredibly valuable for detecting fraud and providing an objective source or information about the events leading up to a crash.