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Event Data Recorders and the
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If you want to BUY one of these systems, please don't call me! Visit the distributors at http://www.cdr-system.com/, where purchasing a system sometimes gets you free tuition to a class on how to use it, which is a REALLY good thing. Alternatively, you could go directly to Bosch's CDR website. Either way, don’t call me, because I don’t sell the kits, I'm just a humble user. Also, please note that this technology is changing almost every day, so I'll do my best to keep this page updated, but new information may come out at any time, consider yourself warned! There, with all that out of the way, we can move on to more important matters.
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The generic term for any device which records information about particular events, such as crashes or airbag deployments, is commonly called (intuitively enough) an Event Data Recorder, or EDR. There are some dedicated OEM and aftermarket EDR systems for airplanes, Railroad Engines, ships, and heavy trucks. There are some aftermarket passenger vehicle EDR-systems which are usually used for fleet applications. I'm not going to discuss any of those. No passenger vehicles currently sold in the US have a dedicated EDR system. The closest thing we've got is that some cars have some EDR functionality built into various components. This functionality is usually found in the airbag contol module (ACM), but may also be found in the engine controller or Powertrain Control Module (PCM) of some vehicles. THESE are what I'll be discussing on this webpage. For ACMs the real job is to monitor the car's status, determine when the car is experiencing an event which meets airbag deployment criteria, and deploy the belt tensioners/airbags/etc. in a timely fashion. The module is working in a black closet with almost no information about the car and none about the environment and is trying to predict what's coming! The EDR-aspects of ACM (and PCM) functionality have been a secondary job at best. The goal of such recording was initially contemplated as a means of providing information to investigators about the actual crash environment the module was experiencing when it decided to either fire the bags or not. Better understanding of how crashes occur in the real world and what causes people to get hurt can lead to an improvement in overall safety for everyone. The diagnostic kit required to access the currently available crop of EDRs is sold by Bosch (who purchased this business unit from Vetronix a few years ago), and is called the Crash Data Retrieval System, or CDR-Tool. Because Vetronix originally sold these devices, you still sometimes hear their name come up, but they are out of this business, AFAIK. These EDR systems do not record audio (voices) or video, direction of travel, location, date, time, who is in the car, phone operation, or any history regarding where you've been or how fast you have driven (except for the few seconds prior to a crash, as noted below). There may be some other systems which contain some of those things, like OnStar, but the "black box" of the EDR does not, and that's all I'm discussing here, and it's all the CDR kit can access. The data from these EDR modules has been used in crash investigations across the country to help determine what happened during a crash. It has also been used in legal matters to clear or convict people. See http://harristechnical.com/cdr.htm for a list of legal cases and state laws regarding EDRs. Questions of data ownership and accessibility to various types of investigators has also been a topic of much discussion. These issues seem to getting settled slowly on a state-by-state basis through legislation and case law. Up to now, manufacturers have each approached EDRs in their own way, but in August 2006, NHTSA issued a rule governing what data an EDR must record when a car has one. In January 2008, they issued their updated Final Rule which addressed some of the petitions they got after the first Rule was announced. It now applies to cars built after 01SEP2012. It mandates a list of things that an EDR must record if the car has an EDR which is intended to be downloaded after a crash. Think about that for a moment: if a car doesn't have an EDR intended to be downloaded after a crash, then the rule does not apply. As with many laws, this 200+ page beast will require some interpretation as it gets implemented. Many cars, though, already have some form of EDR in them, and NHTSA has said that if manufacturers stop putting EDR functionality in their cars, NHTSA will revisit the issue of mandating them. The regulation is technically called "49CFR Part 563", but I'll just call it The 563 Rule. The actual text from the 14JAN08 Federal Register can be downloaded in PDF format by CLICKING HERE. you can find the original (now obsolete) rule online if you look about a bit. In addition to specifying what data must be recorded and at what rates, the 563 Rule includes some survivability requirements (which should be a piece of cake for current EDRs, IMHO). The "must-record" data includes some pre-crash data as well as a lengthy crash pulse. The Rule also requires manufacturers make a tool or translation device to download that data available to the public within 90 days of a car’s release for sale. It does not require them to give away these decoding devices, but rather that they be commerically available. Affordability is not addressed. The Rule does not require that Bosch be the outlet, and I am sure there will soon be more players in the EDR-downloading equipment market. The Bosch kit may continue as the only device to access GM/Ford/Chrysler/some others, but there will probably be kits from one or more other companies (i.e. OTC, B&B, Drew, or the OEM themselves) to access the other dozen or so manufacturers whose products will be covered by the rule.  To the right is an example of an airbag control module from a GM vehicle (click on the thumbnail for the full picture). GM calls these units Sensing and Diagnostic Modules (SDM), while the Ford version is called a Restraint Control Module (RCM). You'll notice that it's not BLACK, despite the common terminology. They are almost all silver. The SDMs measure about 4x4 inches across, and are  about 1.5 inches high, with a big yellow plug on one end and an arrow to indicate FORWARD as installed. Yellow plugs are used throughout the airbag system in all US cars, perhaps to make those connectors easy to find. MFES is one of the several hundred companies nationwide equipped with the CDR system (shown in the photo to the left), having been one of the very earliest adopters of this technology. The CDR system can download the airbag module data from some GM and Ford vehicles after an airbag deployment or in some cases, a non-deployment event. It is the same tool used by NHTSA, GM, and Ford in their investigations. The coverage, locations, what pre-impact and post-impact data gets collected, and best data retrieval procedures vary by manufacturer, so this page will discuss each separately (GM / Ford).
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| Version 3.0 shipped in January 2008, which included the addition of several Chrysler products. Version 3.5 is shipping as I write this. The vehicle coverage list for this and earlier software versions can be found on the Crash Data Group website. | |
| General Motors (Cadillac, Chevrolet, Buick, Olds, GMC, Pontiac, Saturn, Saab, Geo, Hummer, Isuzu) Of all the OEMs, GM has the largest number of models with publicly accessible data. Some data exists in some GM models as early as 1994, while models newer than 2000 generally have all the pre- and post-impact data discussed below, though there are some exceptions to both rules. The Isuzu and Saab coverage is very limited. |
Ford (Ford, Lincoln, Mercury) Ford coverage on some models goes back to 2001, but is much less comprehensive than GM, though the list of covered vehicles is growing with each update, including the about to be released Ver2.9. There are a bunch of Ford RCMs not covered by either 2.8 or 2.9 that we will probably never get access to for what have been termed "internal/supplier" reasons, though some of them may get PCM coverage eventually. See below for more on PCMs. |
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Chrysler and Bosch inked a deal in 2006 or so, and coverage has been slowing coming along starting in early 2008 with Ver.3, with some models covered back to 2005. This does NOT include any Mercedes models, as they are two separate entities again. The Chrysler add-on included a LOT of new direct-to-module cables. Even though I have a software update subscription, the new hardware cost me $1300. Ouch. The Owner's Manuals for various '06 and '07 Dodge vehicles contained this interesting blurb: "In the event of an airbag deployment, your vehicle is designed to record up to 2-seconds of specific vehicle data parameters (see the following list) in the event data recorder prior to the moment of airbag deployment. Please note that such data are ONLY recorded if an airbag deploys, and are otherwise unavailable...Parameters that May Be Recorded: DTCs, “Time” of airbag deployment (in terms of ignition cycles and vehicle mileage), Airbag deployment level (if applicable), Seatbelt status, Brake status (service and parking brakes), Accelerator status (including vehicle speed), Engine control status (including engine speed), Cruise control status." I have heard from others who should probably know about such things that Chryslers prior to that really have nothing, and furthermore, Chryslers only record events. There is no recording of non-deployment events. To visit a page that discusses this issue with respect to JEEPS, CLICK HERE, All Other OEMs According to NHTSA, "65-90% of model year 2004 passenger vehicles" of most manufacturers have some EDR capability built into either their ACM or other on-board systems. NHTSA also noted that "Honda, BMW and other vehicle manufacturers record small amounts of crash data." while they cited Ford, GM, and Toyota as having "what would be considered a large amount of crash data." The Bosch CDR kit is the only publicly available tool to download crash data, and the coverage list cited above should be examined for coverage. The OEM's ability to read their own data remains a hot topic of debate. Honda: One '05 CRV download done in Japan for a Northern Hemisphere client took months to get, but provided Seatbelt status for driver and right front, Driver's seat position, Passenger seat empty or occupied, Which airbags deployed, and Delta V. The '06 MDX and Acura TL reportedly has seatbelt buckled, seat weight sensor, brake on/off, but no collision pulse. Earlier modules often just have "Parameters for deployment were met" or words to that effect. Some new-platform '06 models reportedly can be accessed by a dealer with the "new computer system" which can scroll through a number of recorded parameters if the battery has not been disconnected for too long. After a time without power, though, this data may go away. Toyota, long rumored to be in talks with Vetronix, stepped away from the table back in 2007 or so. Downloads used to require a visit to or from factory personnel, if you could get it done at all, but this is changing as a result of the 2009-2010 sudden acceleration issue. Toyota has now supplied multiple download kits to NHTSA, and perhaps others working on their behalf, for use in their investigations. They have generally stated that they do not believe the system is reliable enough to serve any reconstruction purpose, so they won't provide the data. I don't think anyone in this business really believed them about the uncertain reliability part back then, and this position may come back to bite them, I think, as they now try to use EDR data to support the position that sudden acceleration cases are not the car's fault. As of early 2008, there were rumors of a different “Asian” company coming onboard with Vetronix soon, but it hasn't happened as of July 2010. An '06 Mercedes E350 involved in one case reportedly was downloaded by a road-service-technician from the dealership after some sort of side-event. The data he could access was associated with fault codes for the side curtains or side bags, and included the odometer reading at the time of the event, the current odometer reading, the speed at the time of event, abs on/off, the number of ignition cycles without the fault reoccurring, and brake status (ON/OFF). It's not clear how confident we could be that the speed a fault code being recorded was the speed at the event itself. Perhaps we'll get to do more research on that once the kits become available. Factory download reports for '04 Volvo XC90 show delta-V, crash pulse, vehicle info, and some diagnostic stuff. I thought it was interesting. Volvo continues to be inaccessible by public tools, though. Nissan/Infinity have data that might be accessible by the dealer, but more likely by the manufacturer directly. The modules out there so far reportedly do not have speed, but it might become an available parameter in 2007. Some Hyundai data may be available either by way of the dealer's factory scan tool, or the OTC i-pro scan tool. The OTC website used to say that this tool has "ABS and air bag crash data for OEMs that support it" though it's not clear what that really means, and is no longer listed on their website (July 2010), and some internet chatter I found suggests that the software was not updated after 2002, so maybe not so much, eh? One wonders about their Genisys scanner, though. Reportedly, Audi A3's could store up to 3 crashes, but newer ones get only 1 before requiring replacement. BMW has publicly stated that they don't record data and won't do so until mandated to, because their customers don't want it. That said, I know one law enforcement guy who has seen the printout from a 1999 M3 with speed, occupant status, and some other stuff. Either the M3 was really special, or there's something there that us mortals are just not going to get access to. If the case is big enough, and you've got a search warrant or similar pull, Kia will send someone out from Kia of America in California to download the codes in a crash-involved event. In one pedestrian case with no deployment the effort resulted in no useful data, but in one case with a 2006 Kia Spectra it included an acceleration and delta-V. It's not clear what data might be in there for deployment event for other models or years. Many observers anticipate big changes in this arena with the advent of The 563 Rule, when most everyone will have to make the data available. If they drag their feet too much (either by making public-tools too hard to obtain or disabling their non-compliant modules), NHTSA may step in the way they did with OBDII regs, and nobody wants that, so compliance seems likely, after a fashion. | |
| General Motors Pre-crash The data for essentially all pre-2000 GM cars contained no pre-crash data, but include driver's seatbelt status (buckled/unbuckled), some airbag system diagnostic information, and the crash pulse. The 2000 and newer cars generally include those things along with the vehicle speed, brake status (ON/OFF), throttle position, and engine RPM for about 5 seconds prior to impact. Though there are exceptions to both of these generalizations. |
Ford Pre-Crash Currently supported Ford RCM modules do not record any significant pre-crash data, but they do have driver's seatbelt status (buckled/unbuckled), some airbag system diagnostic information, and the early part of the crash pulse. The recorded crash pulse can include a tiny portion of the pre-wake-up accelerations, but that’s it. See warnings regarding the PCM for some vehicles below. |
| General Motors Post-crash SDMs record the calculated post-impact delta-V, and report it in 10ms intervals for up to 300ms in some modules, less in others. Seatbelt switch status (buckled/unbuckled), airbag warning lamp condition, key cycles at deployment, key cycles at investigation, deployment command times, and some other parameters may also be recorded, depending on the module type & manufacturer used in that vehicle. This is what the Delta-V (change in velocity) data may look like when it is recorded:  Some of the newer Epsilon-class cars may also have information regarding steering wheel position, ABS activation, both Throttle Plate position and Throttle Pedal Position, and more. |
Ford Post-Crash RCMs record the acceleration pulse and the calculated delta-vee in the longitudinal direction each 2ms for approximately 70ms after Wakeup, and in the case of 2001 Taurus/Sables also in the lateral direction (which I think is only accessible with the right early software version). Additionally, RCMs record deployment command times for driver and passenger first and second stages (for both frontal and side airbags), DTCs when they exist, and more. If the second deployment stage isn’t necessary for a particular crash, it will be “disposed of” about 100 ms later in order to ensure that no unused pyrotechnics remain in the car after a deployment. The timing data will tell this tale. An example of Ford data looks like this:  Several researchers have noted that the current Ford modules almost never get a full crash pulse due to their short post-wakeup recording length. The length is enough to get pertinent information about the vehicle environment in the part of a crash where an airbag might help, but doesn't capture any of the long-pulse stuff where airbags probably shouldn't deploy anyway. This is part of the philosophical difference between Ford and GM EDRs. These differences will go away with the advent of the 563 Rule. More detail on recorded data will be forthcoming, after I get to play, uh, experiment, some. |
Some GM SDM Nuances
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Some Ford RCM Nuances
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The literature generally concludes that SDMs and RCM do a pretty good job of recording the data they are provided, and that data generally does a pretty good job of describing the vehicle's operational environment during a recorded event. In addition to unpublished work by the OEMs to verify their systems' accuracy, Rusty Haight at CSI has conducted independent testing to compare the SDM recorded data to an IST accelerometer installed in the test car. The results showed good correlation between the two: the GM-CDR reported delta-vees for deployment-level events were within approximately 0.3 miles per hour of those generated by integrating the IST accelerometer data, with crash-durations matching within a few thousandths of a second. For low-speed events (particularly non-deployment events) the SDMs may miss the first few miles per hour change in velocity before the system wakes up, and the algorithm is enabled. This means you gotta be careful in applying this data to this type of event. Rusty's paper with this material was titled "Automobile Event Data Recorder (EDR) Technology - Evolution, Data, and Reliability" and was presented at ITAI in Nov. 2001. It used to be online, but it appears to have been taken down as of July 2010. The Wisconsin State Police have conducted some testing which showed SDM-recorded pre-crash speeds were right in line with the radar-measured values. This testing was reported in "Crash Data Retrieval System Validation Testing, Wisconsin State Patrol Academy, Nov.2, 2001, Tpr. Tim Austin", a copy of which can be downloaded by clicking here. Additionally, there have been a number of papers published at ESV conferences and through SAE which address the question of accuracy in various circumstances, including the following:
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| Starting in late 2005, the CSI-certification process has shifted to being a two-layered affair: The first layer is "Technician", which is primarily concerned with getting and preserving the data using CDR equipment. The second layer is "Analyst" which is primarily concerned with interpreting the data so obtained. Training classes have occasionally been available from Vetronix themselves, but the only training listed on their website is from CSI. Additionally, IPTM offers a class titled "Methodology and Techniques of Crash Data Retrieval" quite frequently around the country. |
SUV Tangles with Camaro
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Car Attacks Grocery Store
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Rental Car Blues
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The Suicidal Deer and the Sunfire
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Some US tax-dollars go to pay for investigations of severe roadway accidents and the results are public documents. Some of them are pretty neat. Here's the NHTSA Special Crash Investigation (SCI) Search page. You can tailor a search for vehicles which may have downloadable EDRs, and then hunt through the reports for ones where they report the results of such a download. Some of the EDR-equipped vehicles involved in SCI-cases include there:
RPT790056158.pdf '97 Buick Skylark hits guardrail, no deploy. RPT790052054.pdf '97 DeVille takes an Olds in the door. RPT393037358.pdf '98 DeVille takes a Jeep in the door. RPT238027019.pdf 2000 Silverado tangles with a G20 van and loses. BIG DV. RPT452027190.pdf '01 Chevy pickup with hand-controls rearends slower truck. Long Pulse. RPT790051118.pdf '00 Sable with Lat & Long, sideswiped then frontal RPT931057866.pdf '01 Chevy Pickup leaves road & tumbles RPT238037978.pdf '99 Olds Alero deploy for no apparent reason RPT393033560.pdf '99 Grand Prix Inflator Problem during a 30mph DV frontal |
-There WILL be hardware introductions soon (chief among them a new High-Speed CAN box to talk to the Ford PCMs, but also various cables which may also be purchased separately as needed.) The upcoming High-speed CAN box is DIFFERENT from the recently introduced blue Low-speed CAN box. _sigh_ -Version 2.9, which is a DLC-only software upgrade which gets access to the RCM in a bunch more Fords and more 06-07 GMs was supposed to ship on Monday 05Feb...Haven't heard if it happened, though. -PCM access with more good stuff will be a hardware upgrade, and should be coming SOON (maybe June-ish? Maybe a little earlier if things go well?), but will not be covered by the software subscription. I'll talk more about PCMs after we get access to them in our sweaty little hands. -About the same time, a software update should arrive with coverage for one family of Chrysler vehicles (but not Mercedes Benz). More Chrysler coverage will follow. -The 49CFR563 (Part 563 Rule) on EDRs looks to make a lot of headaches for the OEMs, and though standardization is a nice idea, there may be unintended consequences. In part, the rule mandates that IF a vehicle has any recording, it must meet an extensive list of parameters. One unintended side-effect of the rule is that if an OEM has an EDR (maybe even a pretty good EDR) that doesn't meet all the requirements on 9/1/10, they may just disable the units they make after that (maybe by popping the EEPROM out of modules before shipping them?) to avoid breaking the law. We're from the government. We're here to help. -There's a Ver2.81 patch to fix Silverado issues primarily (maybe only?)...It's on the conference CD, it's also reportedly going to be posted at the Vetronix website. If I've understood correctly, the software didn't recognize some supported trucks as actually being supported. -CDR-Tool Kit prices will go up with Ver2.9. A limited number of 2.8Kits are on the shelf at the old price, and when they're gone, they're gone. While I expect NHTSA to use the specter of an OBDii-type mandate to help goad the OEMs into incorporating Rule 563-compliant EDR functionality in their cars, I don't expect plug-standardization (ala the ubiquitous OBDii Diagnostic Link Connector) any time soon. Or ever. We're going to have dozens of little cables in the box. Glad I bought a full-sized van for carrying stuff in!
-Ver2.8 has updates for GM and Ford, and comes with two new cables and a new interface box to handle CAN-bus cars. -The Ver 2.8 software will work with the old interface box, but that box can't talk to CAN-bus cars. -If you bought the Ver2.7 back in 2005 - your new cable should be there soon, mine has arrived. -If you bought the Ford add-on, you may have a cable (3274) that needs re-working by Vetronix. -The Chevy Aveo is really a DaeWoo Kalos with unreadable Siemens modules, so it will not be supported by CDR. -A private analysis of 68 CDR files showed approximately 6±2.5 key cycles per day...I thought that was interesting -The Help file has an error: for the 2006 Cadillac SRX, use cable 2003293 -Even though the 2.7/2.8 software may ACCEPT a Jaguar VIN, it can't decode Jags. There are no plans for coverage, and spoofing will not work. Thanks to Jeff Weger 02/21/2006 -When downloading via DLC in vehicles which use GMLAN (module cables 02003320, 02003321) such as the '05 Cobalt, leave the key out of the ignition. Per Jeff Weger 02/13/2006 -Ford Sport-Trac will be covered in the next software release...date unknown. Per Jeff Weger 02/03/2006 -Lately, I've been using an old Libretto 50CT for downloads: so small it fits inside the CDR case! -Jim Harris keeps a list of CDR-related legal cases, as well as state-by-state CDR laws: http://harristechnical.com/cdr.htm (My thanks to Brad Muir for this tip.).... (My thanks to Brad Muir for this tip.) (My thanks to Gary Johnsonfor this tip! - added 08/01/2001) (My thanks to Gary Johnsonfor this tip! - added 08/01/2001) |
Copyright 2000-2010 by Wade Bartlett
Mechanical Forensics Engineering Services, LLC.
This page created on 08-SEP-2000, and last modified 29-JULY-2010
Mechanical Forensics Engineering Services, LLC.
This page created on 08-SEP-2000, and last modified 29-JULY-2010