Crash Data Retrieval (black boxes)
Our offices can download electronic data from passenger vehicles using the Crash Data RetrievalTM (CDR) system. The electronic data is stored in different vehicle modules depending on the type of vehicle and as such, a blanket term is used – Event Data Recorder (EDR). Most newer vehicles record data of some type, but only certain manufacturers allow after-market downloading of the data. Currently, these manufacturers are General Motors (Chevrolet, GMC, Buick, Pontiac, Oldsmobile), Ford (Mercury, Lincoln), Chrysler (Dodge, Plymouth) and Toyota (Lexus, Scion). Other vehicle manufacturers likely store data in their vehicle air bag systems, but the manufacturer needs to be contacted directly, usually through their legal department. However, starting in September 2012, essentially all vehicles with an EDR must be commercially downloadable. Check here for currently downloadable vehicles – http://www.cdr-system.com/resources/coverage.html.
It should be noted that vehicle EDR’s are normally part of the air bag system. The primary purpose of an Air Bag Control Module (ACM) is to deploy the air bags and seat belt pre-tensioners. After that task has been completed, data is written to the EDR if sufficient power remains in the system. This is the primary difference between an EDR in a vehicle and a black box in an airplane: the black box in an airplane is intended to continuously record information, whereas the EDR in a vehicle records data only if a sufficiently aggressive event occurs.
Data varies extensively depending on the manufacturer, vehicle and model year of the vehicle. Some 1994 model year General Motors vehicles were downloadable, but the data was largely limited to driver’s seat belt status and impact severity (delta-V). However, in model year 2000, pre-crash data was available in General Motors vehicles for approximately 5 seconds leading up to the collision. This pre-crash data includes wheel speed, braking (on/off), accelerator pedal percent and engine RPM. Current General Motors vehicles provide this data and more, including driver and front passenger seat belt status, steering wheel angle, cruise control status as well as longitudinal and lateral delta-V.
Ford vehicles are downloadable starting with model year 2001 for some models. Like General Motors, the data depends on the vehicle model and year. Unlike General Motors, Ford data may be contained in both the Airbag Control Module (ACM) and the Powertrain Control Module (PCM), necessitating a more complex download procedure. Older Ford vehicles tend to contain less crash data than General Motors or Chrysler.
Chrysler vehicles are downloadable starting with model year 2005 (Durango only), with many more vehicles being downloadable with model year 2006 and newer. Some Chrysler vehicles can record extensive pre-crash data, including such parameters as steering wheel angle, yaw angle, and stability control engagement. However, many Chrysler vehicles do not record data unless the front air bags deployed. Many General Motors vehicles will record data even if the air bags do not deploy.
Toyota vehicles are downloadable primarily for 2006 and newer vehicles, although select vehicles are downloadable as far back as 2001. Toyota vehicles provide pre-crash data similar to General Motors, in that speed, braking, accelerator pedal and engine RPM are recorded. Driver and passenger seat belt status may also be recorded. Also like General Motors, Toyotas may record data even without an air bag deployment.
