Reference Guide
About
Event Data Recorders (EDRs) are electronic systems installed in modern vehicles that continuously monitor and record vehicle operating data. When specific trigger events occur - such as a crash, sudden deceleration, or airbag deployment - these systems capture and store a snapshot of critical pre-crash and crash data.
CDR (Crash Data Retrieval) technology provides investigators with objective, time-stamped data from these recording systems. This data typically includes vehicle speed, throttle position, brake application, steering input, seatbelt status, and crash forces (delta-V). The recording window generally captures several seconds of pre-crash data and the crash event itself, providing crucial information for reconstruction and analysis.
Different vehicle manufacturers use varying terminology and system architectures. Bosch CDR systems interface with a wide range of manufacturer modules, GIT of America specializes in Kia and Hyundai EDR extraction, and Tesla maintains proprietary EDR systems accessible through their specific tools. Each system requires manufacturer-specific hardware, software, and trained operators to ensure proper data extraction and interpretation.
Understanding module types, compatibility requirements, and proper extraction procedures is essential for successful data recovery in crash investigations.
What is CDR?
Crash Data Retrieval (CDR) is the technology and process used to extract data from a vehicle's Event Data Recorder (EDR). When a crash or triggering event occurs, the EDR captures and preserves critical information from the moments before, during, and immediately after the incident.
Data typically retrieved through CDR systems includes:
- Pre-crash vehicle speed - Speed measurements in the seconds leading up to impact
- Engine RPM - Engine revolutions per minute during the event sequence
- Brake application - Whether and when brakes were applied, including duration and force
- Throttle position - Accelerator pedal position throughout the event
- Steering input - Direction and degree of steering wheel movement
- Seatbelt status - Whether occupant restraints were buckled
- Airbag deployment timing - Precise timing of airbag system activation
- Delta-V - Change in velocity measurements indicating crash severity
- Vehicle systems status - Various warning lights, traction control, ABS activation
The specific data elements available vary by vehicle manufacturer, model year, and the EDR system installed. Recording windows typically span 5 seconds of pre-crash data, though this can vary. Modern systems may record additional information including multiple impact events, rollover sensing data, and advanced driver assistance system (ADAS) status.
Module Types
ACM
Airbag Control Module
ACU
Airbag Control Unit (Kia/Hyundai)
ADS
Advanced Driver Systems
ASCM
Active Safety Control Module
DCM
Diagnostic Control Module
OCS
Occupant Classification System
PCM
Powertrain Control Module
PPM
Pedestrian Protection Module
RCM
Restraint Control Module (Tesla)
SDM
Sensing Diagnostic Module
Disclaimers
Manufacturer Coverage: This reference covers Bosch CDR systems, GIT of America EDR tools for Kia/Hyundai vehicles, and Tesla EDR systems. Each manufacturer maintains their own compatibility lists and technical specifications. Vehicle compatibility may vary by market, production date, and specific vehicle configuration.
Data Sources:
- Bosch CDR: Based on Bosch CDR Software vehicle compatibility documentation
- GIT EDR: Based on GIT of America EDR tool specifications and supported vehicle lists
- Tesla EDR: Based on Tesla EDR manual documentation and system specifications
Information is current as of the latest available manufacturer documentation. Always verify with manufacturer documentation for the most recent updates.
Professional Use: This tool is intended for use by trained traffic crash investigators and reconstructionists. Always verify module compatibility before attempting data download. Consult manufacturer guidelines and training materials for proper procedures.