SAMAC Engineering - Event Data Recorders

Event Data Recorders (EDRs)

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Recorded data may be available from vehicles after a collision. This data is stored in event data recorders, often incorrectly referred to as “black boxes”. Currently data can be found in one of 3 types of systems, depending on the type of vehicle and fleet owner. These are:

  1. Passenger vehicles: Data in passenger vehicles is normally stored in the Event Data Recorder (EDR; given a different name by each manufacturer) as the result of a collision or airbag deployment, and can include vehicle speeds, speed changes, brake status (on/off), throttle position, and driver seatbelt use, among others. Depending as well, some Fords have additional data stored in their powertrain control module (PCM). Vehicles for which data may be available include most General Motors, Ford, and Chrysler vehicles, plus newer Toyota, Honda, and Nissan vehicles. For specific models with data that may be available, please click here for a pdf list. A week of training is required every two years along with specialized equipment in order to download and interpret the data. SAMAC currently has 5 experts with the training and equipment to download these vehicles. Although the retrieved data can be very useful, there are many times when the data is not available, retrieveable, or applicable.

    Click here for more information on passenger vehicle event data recorders.

  2. Heavy Vehicle Event Data Recorders (HVEDRs): Heavy vehicles, such as tractor-trailers, typically have a computerize “brain” that controls power generation systems, emission systems and engine performance. It is referred to as an electronic control module (ECM) and often contains an event data recorder (EDR) capable of storing event data. Whether a heavy vehicle can store data, and the type of data stored, depends on the manufacturer and model year of the engine not the vehicle. Most current heavy vehicle engines store data (i.e. Caterpillar, Cummins, Detroit Diesel, Mack, Mercedes Benz, International, Volvo, Paccar, etc.). Tyler Dyck is trained to safely and correctly obtain the information from HVEDRs, and will typically perform the download with the assistance of a technician from the applicable engine manufacturer (i.e. to use their equipment/software as it is not cost effective to have the equipment/software in-house). Other heavy vehicle systems capable of storing data include: ABS modules, GPS/tracking systems, on-board video, airbag control modules, etc.

    Click here for more information on heavy vehicle event data recorders.

    HVEDRs vs. Passenger Vehicle EDRs

    • Do not sense impacts; records when an event trigger (usually a change in wheel speed) is exceeded.
    • No internal power (needs vehicle power for about 15+ seconds to store the data).
    • Recovering tools/software programs both read and write (i.e. data can be overwritten).
    • Generally less tolerant of damage.
  3. Diagnostic codes, etc: These codes register the status of various systems in a modern vehicle and are routinely downloaded by vehicle dealers and repair shops during service checks. These downloads can also be obtained by using a commercially available tool (such as Snap-On) with the appropriate software. The data is of limited use in accident reconstruction except for manufacturers that might want to verify that there were no fault codes for their airbag or other safety systems. Although typically performed by dealers, SAMAC has the capability and training to perform such downloads.

For additional information, please call Steve MacInnis or Tyler Dyck at 403-243-2238.

Our Event Data Recorders Team