Forensic Analysis & Expert Witness Services
Automotive Computer and Electronic Control Systems
Your Subtitle text

Forensic Analysis Services

ASA is typically retained to perform analyses of various on-board automotive control systems, including Event Data Recorders (EDR),  Antilock Braking Systems (ABS), Electronic Power Steering (EPS, Electronic Throttle Control (ETC) and Supplemental Restraint Systems (SRS). 

With respect to crash event data in passenger vehicles and light trucks, there are both public and proprietary data retrieval tools which can access EDR (Event Data Recorder) data.  The data retrieved is normally listed as raw hexadecimal data.  Hexadecimal data is a base-16 numeric representation of binary memory data, and as examples, that data can be encoded at numeric, signed-numeric, state-condition, bitmap and ASCII values.

The most common data retrieval tool specifically designed to retrieve and translate such data from select SRS ECUs, and from select Engine ECUs,  is the Bosch/Vetronix CDR ®,  and this tool is employed by most vehicle crash investigators.      The CDR operates using a serial data interface , and the CDR capabilities are available for a specific vehicle application set.   There are CDR options for data retrieval from the J1962 port (OBD-II connector) or from an ECU directly, both employing a serial data interface.  However, even within the CDR vehicle application set, the CDR reports do not fully translate all of the source hexadecimal data.   

However, there is EDR data in vehicles and ECUs not covered in the CDR application set, and many investigators, when confronted with a vehicle outside of that CDR application set, do not pursue EDR data retrieval.  Of course, many manufacturers and EDR suppliers can access such non-CDR-coverage  data with proprietary data retrieval tools, however, the public access to such proprietary tools is usually nil.  Additionally, when manufacturers and EDR suppliers provide data to other parties, that data can be seriously incomplete (or incompletely translated). 

ASA has been independently retrieving and translating EDR data since 1995.  This includes data from Electronic Control Units (ECUs) not included in the CDR application set, and includes  Domestic, Asian and European passenger vehicle applications.

Additional to the CDR tool, ASA uses both serial and direct-EEPROM proprietary data retrieval & translation methods.  An example of ASA Direct EEPROM data retrieval to provide translated EDR Event Data Information is shown on the Analysis Examples page.  

ASA analyses are conducted in accordance with the following standards,  as appropriate:

ASTM E2493-07,   Standard Guide for the Collection of Non-Volatile Memory Data in Evidentiary Vehicle Electronic Control Units

ASTM E 860 – 97,   Standard Practice for Examining And Testing Items That Are Or May Become Involved In Litigation

ASTM E 1188 – 95,  Standard Practice for Collection and Preservation of Information and Physical Items by a Technical Investigator

ASA analyses of various physical/system/electrical/computer faults can lead to evidentiary findings which sustain allegations of proper vehicle systems operation, or conversely, they can lead to system and component tests which prove correct operation.

Website Builder