
Crash Data
Retrieval Kit




Sensing Diagnosing
Module's

Event
Data Recorders


Diagnostic Link
Connector


On-Board-Diagnostics
(OBD) II
Rev.:09/01/2008 |
 
| Accident Analysis & Consulting
is certified by
Vetronix Corporation/Bosch
Group to operate Crash Data Retrieval Systems by
General Motors (GM) and Ford. |
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Downloads pre-crash and
crash data from a vehicle's air bag module
to a laptop computer. The Windows® based CDR
software presents the data in easy-to-read
graphs and tables.
Crash Data
Retrieval System Overview
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What data can be
downloaded from the vehicle's air bag
module*
Recorded data depends on
vehicle make, model and year. The following
data is typical of what is found on a newer
GM vehicle.
-
Vehicle
speed (5 seconds before impact)
- Engine speed (5 seconds
before impact)
- Brake status (5 seconds
before impact)
- Throttle position (5
seconds before impact)
- State of driver's seat
belt switch (On/Off)
- Passenger's air bag
enabled or disabled state (On/Off)
- SIR Warning Lamp status
(On/Off)
- Time from vehicle
impact to air bag deployment
- Ignition cycle count at
event time
- Ignition cycle count at
investigation
- Maximum deltaV for
non-deployment event
- deltaV vs. time for
frontal air bag deployment event
- Time from vehicle
impact to time of maximum deltaV
- Time between non-deploy
and deploy event (if within 5 seconds)
*Depending
on the particular vehicle, all or a
subset of this data may be available.
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History
The relationship between General
Motors (GM) and Vetronix began in 1984. GM
selected Vetronix to develop the first event
data retrieval unit in 1990 (GM use only).
Afterwards, GM awarded Vetronix an exclusive
contract to develop the crash data retrieval
(CDR) system for GM and the aftermarket. The
crash data retrieval (CDR) system became
available to the public in March 2000.
Ford contracted Vetronix to develop software
that will interface with the Crash Data
Retrieval System (CDR) and enable users to
download crash data from select Ford
Vehicles. The first Ford update (software
and cable) was
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Frequently
Asked Questions about the CDR system |
Q: What is an air bag module?
A: The air bag module is the vehicle's “computer” that
controls air bag deployment. Since 1990, recordable air bag modules
have been installed in select GM vehicles. SDM, Sensing and
Diagnostic Module, is the name given to air bag modules used in
General Motors vehicles from 1994 to present.
Since 1998, recordable air bag modules have been installed in select
Ford vehicles. RCM, Restraint Control Module, is the name given to
air bag modules used in Ford vehicles from 1998 to present.
Q: Will data only be recorded if the air bags deploy?
A: No, data is recorded in both Deployment and Non-Deployment
Events.
Q: What is a Non-Deployment Event?
A: There are two types of air bag module (SDM) recorded crash
events. The first is the non-deployment event. A Non-Deployment
event is an event severe enough to “wake up” the sensing algorithm
but not severe enough to deploy the air bag(s). It contains
Pre-Crash and Crash data. The SDM can store up to one Non-Deployment
Event. This can be overwritten by an event that has a greater SDM
recorded velocity change (Delta-V). This event will be cleared by
the SDM after the ignition has been cycled 250 times (about 60 days
of normal driving).
Q: What is a Deployment Event?
A: The second type of SDM recorded crash event is the
Deployment Event. It also contains Pre-Crash and Crash data. The SDM
can store up to two different Deployment Events, if they occur
within five seconds of one another. The first deployment event will
be stored in the deployment file (this would have been the event
that deployed the air bag) and the second Deployment Event will be
stored in the Near Deployment file. Deployment events can not be
overwritten or cleared from the SDM. Once the SDM has deployed the
air bag, the SDM must be replaced.
Q: Why are GM and Ford making this data available?
A: GM and Ford wish to collect air bag deployment and crash
data in order to improve vehicle safety design. They also wish to
support recommendations set forth by the NTSB and NHTSA.
Q: Do other vehicle manufacturers have recordable air bag
modules, and if so, why aren't they releasing this data?
A: Yes, some other vehicle manufacturers have recordable air
bag modules. The amount of information recorded and the Model Year
that they began installing these recordable air bag modules differs
for each manufacturer. The NTSB (National Transportation Safety
Board) and the
NHTSA (National Highway Traffic Safety Administration) have
recommended that all vehicle manufacturers equip their vehicles with
recorders capable of storing crash data.
Q: Has the CDR system been validated?
A: Yes, GM, Ford and
Vetronix have
worked together to ensure the accurate retrieval and presentation of
the recorded data. In addition, independent validation tests have
been performed by
NHTSA, Michigan State Police, Ontario Provincial Police, and
others.
Q: Are there validation studies and reports available?
A: Yes, several
papers and studies
have been published concerning CDR data validation. Please contact
Vetronix for more information.
| Q:What are the potential uses of the data?
A:EDRs can provide information about a crash
that can't be obtained through more traditional
investigation techniques. Police, crash investigators,
automakers, insurance adjusters, and highway safety
researchers can use this information to analyze what
occurred during a crash. The data may help automakers design
better airbag systems and vehicle structures.
EDR data may be useful in determining culpability. For
example, EDR data from a car involved in an August 2002
crash in Florida showed the vehicle was traveling at 144 mph
seconds before it struck another vehicle, killing two
passengers. The EDR data was used to convict the driver of
manslaughter. |
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