Accessing Crash Data from Passenger Cars and Light Trucks

Donan Engineering Co., Inc.’s staff of Traffic Accident Reconstructionists are trained, certified, and equipped with the most up-to-date Bosch Crash Data Retrieval software and equipment to download and evaluate crash data captured by Event Data Recorders (EDRs) in passenger cars and light trucks.  This data is an extremely valuable tool to assist in the analysis and evaluation of traffic collisions.  The Bosch software allows us to access crash data from the following general list of vehicles:

• Most General Motors vehicles model years 1994 through 2008
• Select Ford/Lincoln/Mercury vehicles model years 2001 through 2007
• Select Chrysler/Dodge/Jeep vehicles model years 2004 through 2008
• Limited Isuzu vehicles model years 1998 through 2008
• Mitsubishi Raider’s  model years 2005 through 2007
• Suzuki XL7 model years 2007 and 2008

A complete list of all vehicles that are supported by the Bosch Crash Data Retrieval Tool can be viewed at www.igothit.com.

The type and amount of data that can be downloaded from vehicles supported by the Bosch software varies considerably between model years and manufacturers.  Data is generally recorded in the event of an airbag deployment, and is often recorded in a collision where an airbag deployment is not necessary. 

Figure 1

The early airbag control modules in General Motors vehicles (referred to as the Sensing Diagnostic Module (SDM) by General Motors) model years 1994 through 1999 only recorded crash pulse data (Delta-V) and vehicle status data.  Beginning with model year 2000 and newer General Motors vehicles, five seconds of pre-crash data began being recorded in addition to the crash pulse data and vehicle status data.  The five seconds of pre-crash data includes Vehicle Speed in mph, Engine Speed in rpm, Percent Throttle, and Brake Switch Status (On/Off), all of which are reported at approximately one-second intervals.  Later models also include information regarding steering wheel angle, tire pressure monitors, seat belt status, and a myriad of other potentially useful data.  The pre-crash data is the most valuable information to assist our collision reconstructionists in the complete analysis and reconstruction of a traffic collision.

The airbag control module in Ford-Lincoln-Mercury vehicles (referred to by Ford as the Restraint Control Module, or RCM) model years 2001 through 2007 only records the Delta-V, the vehicle status at impact, and the activities of the airbag control module to deploy restraint system components.  It does not record pre-crash data.

Figure 2

However, beginning with select Ford vehicles model years 2003 through 2007, the Powertrain Control Module (PCM) on vehicles equipped with Electronic Throttle Control (ETC) is capable of capturing 25 seconds of crash data (20 seconds pre-crash and 5 seconds post-crash).  Crash data from 16 PCM inputs/outputs is recorded at 0.2 second intervals.  The primary crash data includes Vehicle Speed, Accelerator Pedal Percentage, Engine Throttle Percentage, Engine RPM, and brake switch on/off status.  The crash data is locked in the PCM memory if the PCM receives a Restraint Deployment Signal from the RCM, indicating that a seatbelt pre-tensioner or airbag deployment event occurred.  If the Restraint Deployment Signal is not received by the PCM, then the crash data can be overwritten by leaving the vehicle ignition on.  Special care must be taken to properly download the PCM data without inadvertently overwriting the data. 

The Airbag Control Module in select Chrysler vehicles has also recently become downloadable via the Bosch Crash Data Retrieval System.  Two seconds of pre-crash data reported at 0.1 second intervals is available, including vehicle speed, brake switch, and percent throttle. 

A recent National Highway Traffic Safety Administration (NHTSA) ruling 49-CFR Part 563 will make the use of the Bosch Crash Data Retrieval software and equipment an even more valuable tool available to collision investigators and reconstructionists.  The ruling requires that all automobile manufacturers of passenger cars and light trucks which are sold in the United States and are equipped with event data recorders standardize the data that is recorded.  The manufacturers must also make the software and equipment needed to retrieve the crash data from the Event Data Recorders available for sale to the general public.  In short, the ruling does not require manufacturers to record data, but states that if they do, then they must record certain data, and the data must be accessible by a third party.  Automobile manufacturers must comply with this ruling by September of 2010.

The Bosch Crash Data Retrieval equipment and software is an extremely valuable tool available to collision reconstructionists to assist in the overall reconstruction of a traffic collision.  As valuable as the information obtained from the Event Data Recorder is, it is important to note that the crash data retrieved from the EDR will not be sufficient as “stand alone” evidence in many “real world” events; a full analysis of the crash is still required.