EDR “BLACK BOX” DOWNLOADS
What is “CDR” and “EDR”?
“CDR” is the acronym for Crash Data Retrieval, and is used to describe the CDR Tool. “EDR” is the acronym for Event Data Recorder, which is a function of the airbag control module or “ACM”. The CDR Tool is a commercially available system comprised of hardware and software that is used by law enforcement, collision re-constructionists, fleet managers and government researchers to access and “image” EDR data which may be stored in control modules found in passenger cars, light trucks and SUVs.
The airbag control module’s potential capability to save data after a crash has caused some to mistakenly refer to it as an “event data recorder” or EDR and moreover the “black box”. In reality, the airbag control module’s primary job is to detect sudden changes in direction and/or rotation and, when appropriate, deploy restraint devices like airbags. The ACM uses certain bits of information including that from crash sensing systems, seat belt related sensors and occupant detection systems to decide whether or not and when to deploy airbags and other restraint system devices. When certain conditions are met, the airbag control module may record data associated with these sudden changes in direction and/or rotation (i.e. a crash) which can later be “imaged” by the CDR Tool.
What gets recorded and when should you image data?
Different make and model vehicles record different amounts of data and a different number of “events”. An “event” is a crash or other physical occurrence which causes a trigger threshold to be met or exceeded. Data from the collision is stored in the airbag control module as either a “non-deployment” event or a “deployment” event. You should ALWAYS image a supported vehicle, even if the impact was so minor that an event was not recorded.
A non-deployment event is a sudden change in direction and/or rotation of the vehicle that “wakes-up” or “enables” the ACM but makes a decision not to deploy any of the safety restraints; for example, hard braking. On the other hand, you could have a deployment event. A deployment event is a sudden change in direction and/or rotation that “wakes up” or “enables” the ACM and is sufficient to warrant a command deployment.
Some of the key data parameters that are recorded in the ACM are listed below, and certain ACM types include up to 5 seconds (or more) of pre-crash data. With the CDR Tool you now have access to a physical, non-biased, representation of what the vehicle was doing 5 seconds prior to impact (typically recorded in 1 second intervals)!
Benefits of imaging vehicle crash data include:
Valuable crash evidence stored in the vehicle
Obtain pre-crash vehicle data
Obtain vehicle speed
Obtain delta-V (crash severity)
Obtain seat belt status
Obtain throttle position
Obtain brake status
Obtain ignition cycles
A proven track record of admissibility at trial
and much more
When the vehicle data is imaged, using the CDR Tool, and used properly, it leads to a collection of data evidence that can be used for a multitude of information regarding a crash. If the data stored is ignored and not imaged, it opens recontructionists and insurers to claims of bad faith and evidence spoliation. Always image the EDR data!
Is the data obtained from an EDR admissible in court?
The simple answer…YES. the data obtained from a vehicle’s Event Data Recorder has been admitted as evidence, along with expert opinion, after extensive admissibility hearing and challenges.