“Thinking Outside the Black Box, Automobile Crash Data Recorders”MTLA Magazine
Article Author: Peter W. Riley
The case looked hopeless. Englebert Falsani had approached me about representing him in his injury claim arising out of a crash at an uncontrolled intersection. Mr. Falsani sustained a head injury in the collision, and had no recollection of its facts. The other involved driver, R. Peter Walker Lousley  acknowledged that while Falsani had the directional right-of-way, Falsani had been speeding. In addition, an accident reconstructionist hired by Mr. Lousley noted that there were no skid marks left by Mr. Falsani’s vehicle, a 2001 Isuzu Hombre .
In a statement to the police the day after the collision, Mr. Lousley asserted that he had entered the intersection at 20 mph. in his 2001 Cadillac Escalade when suddenly Mr. Falsani’s vehicle appeared in front of him at a speed he estimated to be 50 to 60 mph. Mr. Lousley stated that he had applied his brakes and slowed his vehicle, but could not avoid the impact with Mr. Falsani’s vehicle.
Given Mr. Falsani’s total memory loss for the facts of the collision, I was at a loss to determine how I would help him make a recovery in this case. Although I despaired of being able to help Mr. Falsani, I placed a call to Roger Burgmeier, an Accident Reconstructionist. After a brief conversation to which Mr. Burgmeier inquired as to the current whereabouts of the involved vehicles, he calmly informed me that he should have a definitive answer for me in a day or two.
No more than 48 hours later, Roger called me – "Peter, Mr. Lousley is not telling the truth. In fact, Mr. Falsani was traveling at 25 mph. 4 seconds before the collision and 3 seconds before the collision, he applied his brakes, and his vehicle was traveling approximately 12 miles per hour at impact."
"Mr. Lousley, on the other hand, was traveling at 43 mph as he entered the intersection. He never applied his brakes before impact."
Significantly, Roger never went near the accident scene to make these determinations – instead, the use of the CDR (crash data retrieval) system allowed him to access data from the computers in the vehicles, allowing precise determination of pre-accident speed, throttle position and braking.
The "black box"
Since approximately 1992, major automobile manufacturers including General Motors, Ford and Chrysler have been utilizing supplemental restraint systems incorporating air bags. A critical component of the SRS system is electronic component known as the "sensing and diagnostic module" (SDM). This device is responsible for constantly measuring vehicle speed, throttle, brake status, and other data to determine if a crash is imminent and, once it occurs, to deploy the airbags almost instantaniously.
The SDM records two types of events that can provide data useful to accident investigators:
a. Near deployment event:
A near deployment event is one severe enough to "wake up" the sensing algorithm, but one that is not severe enough to actually deploy the airbag. For example, a vehicle may be involved in a crash that does not involve sufficient deceleration to trigger the airbag, or one, which is an offset crash, which does not trigger airbag deployment. Near deployment events are stored in the SDM until one of two conditions occurs.
1. Another near deployment event occurs, or
2. The ignition cycles 250 times.
The data recorded is the last 5 seconds before the crash and the crash data.
b. Deployment event:
In this event, the airbag actually deploys, and once again the SDM stores both pre-crash and crash data. The SDM is capable of storing up to two different deployment events if they occur within 5 seconds of one another. These events cannot be overwritten or cleared from the SDM.
Figure one is example data from a GMC Sierra Z71. In it, the brake circuit status shows that the brakes were applied 3 seconds prior to impact, and were fully applied 2 seconds prior to impact. The vehicle speed rose from 12 mph. 5 seconds before impact to a peak of 25 mph. 2 seconds before impact, and then slowed to 15 mph. 1 second before impact.
The throttle data shows that the throttle was applied approximately one-third of the way 5 seconds before impact, increased slightly to 40 percent both 4 and 3 seconds prior to impact, and then the throttle was released in the last 2 seconds before impact.
Seconds Before AE Vehicle Speed(MPH) Engine Speed(RPM) Percent Throttle Brake Switch Circuit Status
-5 46 1280 2 off
-4 46 1280 2 off
-3 45 1216 2 off
-2 36 704 2 on
-1 36 704 2 on
System Status at Deployment
SIR Warning Lamp Status OFF
Driver’s Belt Switch Circuit Status BUCKLED
Passenger Front Air Bag Suppression Switch Circuit Status Air Bag Not Suppressed
Ignition Cycles At Deployment 633
Ignition Cycles At Investigation 689
Time From Algorithm Enable to Deployment Command Criteria Met (msec) 15
Time From Algorithm Enable to Pretensioner Deployment Command Criteria Met (msec) 15
Time Between Near Deployment And Deployment Events (sec) N/A
Other data that is recorded includes the status of the seat belt, buckled or unbuckled. The data recorder will also show whether or not the airbag warning light was on or off prior to impact, and whether or not the passenger front airbag suppression switch, (the switch that allows operators of vehicle with no back seat to disable the passenger airbag in order to transport a baby seat) was on or off.
Table 2 lists the vehicles, which are currently covered by the CDR System. At present, the Daimler Chrysler Corporation has refused to release the software, which would allow downloading of onboard data captured by the sensing and diagnostic modules in Daimler Chrysler vehicles.
Currently, the CDR System covers over 90 percent of all GM vehicles built since 1996, and the software necessary to download data from 1994 to 1996 model GM vehicles recently became available.
Supported GM Vehicles
1996 1997 1998 1999 2000 2001 2002
1996 Make and ModelBuick RivieraBuick SkylarkChevrolet AstroChevrolet CamaroChevrolet CavalierChevrolet ExpressGMC SafariGMC SavanaOldsmobile AchievaOldsmobile AuroraPontiac FirebirdPontiac Grand AMPontiac SunfireSaturn All models:
1997 Make and ModelBuick CenturyBuick LeSabreBuick Park AvenueBuick RegalBuick RivieraBuick SkylarkCadillac Commercial SpecialCadillac DevilleCadilla EldoradoCadillac SevilleChevrolet AstroChevrolet CamaroChevrolet CavalierChevrolet CorvetteChevrolet ExpressChevrolet LuminaChevrolet MalibuChevrolet Monte CarloChevrolet SilveradoChevrolet SuburbanChevrolet TahoeChevrolet VentureGM1 EV1GMC SafariGMC SavanaGMC SierraGMC YukonOldsmobile AchievaOldsmobile AuroraOldsmobile Eighty EightOldsmobile RegencyOldsmobile SilhouettePontiac BonnevillePontiac FirebirdPontiac Grand AMPontiac Grand PrixPontiac SunfirePontiac Trans SportSaturn All models
1998 Make and ModelBuick CenturyBuick LeSabreBuick Park AvenueBuick RegalBuick RivieraBuick SkylarkCadillac Commercial SpecialCadillac DevilleCadillac EldoradoCadillac SevilleChevrolet AstroChevrolet BlazerChevrolet CamaroChevrolet CavalierChevrolet CorvetteChevrolet ExpressChevrolet MalibuChevrolet Monte CarloChevrolet LuminaChevrolet S10Chevrolet S10 ElectricChevrolet SilveradoChevrolet SuburbanChevrolet TahoeGMC JimmyGMC SafariGMC SavanaGMC SierraGMC SonomaGMC YukonOldsmobile AchievaOldsmobile AuroraOldsmobile BravadaOldsmobile CutlassOldsmobile Eighty EightOldsmobile IntriguePontiac BonnevillePontiac FirebirdPontiac Grand AMPontiac Grand PrixPontiac SunfireSaturn All models
1999 Make and ModelBuick CenturyBuick LeSabreBuick Park AvenueBuick RegalBuick RivieraCadillac Commercial SpecialCadillac DevilleCadillac EldoradoCadillac EscaladeCadillac SevilleChevrolet AstroChevrolet BlazerChevrolet CamaroChevrolet CavalierChevrolet CorvetteChevrolet ExpressChevrolet LuminaChevrolet MalibuChevrolet Monte CarloChevrolet S10Chevrolet S10 ElectricChevrolet SilveradoChevrolet SuburbanChevrolet TahoeGM1 EV1GMC JimmyGMC SafariGMC SavanaGMC SierraGMC SonomaGMC YukonOldsmobile AleroOldsmobile AuroraOldsmobile BravadaOldsmobile CutlassOldsmobile Eighty EightOldsmobile IntriguePontiac BonnevillePontiac FirebirdPontiac Grand AMPontiac Grand Prix2Pontiac SunfireSaturn All models
2000 Make and ModelBuick CenturyBuick LeSabreBuick Park AvenueBuick RegalCadillac Commercial SpecialCadillac DevilleCadillac EldoradoCadillac EscaladeCadillac SevilleChevrolet AstroChevrolet BlazerChevrolet CamaroChevrolet CavalierChevrolet CorvetteChevrolet ExpressChevrolet ImpalaChevrolet LuminaChevrolet MalibuChevrolet Monte CarloChevrolet S1Chevrolet SilveradoChevrolet4 SilveradoChevrolet SuburbanChevrolet4 SuburbanChevrolet TahoeChevrolet4 TahoeChevrolet VentureGMC JimmyGMC SafariGMC SavanaGMC SierraGMC4 SierraGMC SonomaGMC YukonGMC4 YukonIsuzu HombreOldsmobile AleroOldsmobile BravadaOldsmobile IntrigueOldsmobile SilhouettePontiac BonnevillePontiac FirebirdPontiac Grand AMPontiac Grand Prix2Pontiac MontanaPontiac SunfireSaturn All but LS
2001 Make and ModelBuick CenturyBuick LeSabreBuick Park AvenueBuick RegalBuick RendezvousCadillac Commercial SpecialCadillac DevilleCadillac EldoradoCadillac EscaladeCadillac SevilleChevrolet AstroChevrolet BlazerChevrolet CamaroChevrolet CavalierChevrolet CorvetteChevrolet ExpressChevrolet ImpalaChevrolet LuminaChevrolet MalibuChevrolet Monte CarloChevrolet S10Chevrolet SilveradoChevrolet SuburbanChevrolet TahoeChevrolet VentureGMC JimmyGMC SafariGMC SavanaGMC SierraGMC SonomaGMC YukonIsuzu HombreOldsmobile AleroOldsmobile AuroraOldsmobile BravadaOldsmobile IntrigueOldsmobile SilhouettePontiac AztekPontiac BonnevillePontiac FirebirdPontiac Grand AMPontiac Grand Prix2Pontiac MontanaPontiac SunfireSaturn All but LS
2002 Make and ModelBuick CenturyBuick LeSabreBuick Park AvenueBuick RegalBuick RendezvousCadillac Commercial SpecialCadillac DevilleCadillac EscaladeCadillac SevilleChevrolet AvalancheChevrolet AstroChevrolet BlazerChevrolet CamaroChevroletCavalierChevrolet CorvetteChevrolet ExpressChevrolet ImpalaChevrolet MalibuChevrolet S10Chevrolet SilveradoChevrolet SuburbanChevrolet TahoeChevrolet TrailBlazerChevrolet VentureGMC EnvoyGMC SafariGMC SavanaGMC SierraGMC SonomaGMC YukonIsuzu HombreOldsmobile AleroOldsmobile AuroraOldsmobile BravadaOldsmobile IntrigueOldsmobile SilhouettePontiac AztekPontiac BonnevillePontiac FirebirdPontiac Grand AMPontiac Grand Prix2Pontiac MontanaPontiac SunfireSaturn All cars except LSSaturn VUE
THE USE OF "BLACK BOX" DATA IN PERSONAL INJURY LITIGATION
As the foregoing discussion demonstrates, the SDM has the potential to provide crash investigators with precise pre-accident crash data. No longer must a vehicle’s speed be estimated from skid marks or vehicle trajectories combined with crush damage to the vehicles, a fact which is all more the important given that, with the widespread adoption of the ABS brakes, fewer and fewer vehicles are even capable of leaving diagnostically reliable skid marks. This is not to say physical scene evidence is unimportant; rather, it can be augmented by the data from the SDM.
In any case of substantial damages in which an airbag deployment occurred in a vehicle whose SDM is capable of being read, plaintiff’s counsel should endeavor to obtain a reading of the SDM data for all vehicles. In other cases, the SDM should be checked to see if a "near deployment event" registered data about the crash.
It is important to note that this data reading is non-destructive, that is, it can be read by the plaintiff’s expert, and later by defense experts, or vice versa.
The early reading and analysis of SDM data is an important development in crash investigation any personal injury practitioner can use to great advantage. Coupled with other reconstruction techniques, it will hopefully serve to answer issues of crash cause in the future that might otherwise have no clear answers.
 The name is, of course, ludicrously fictitious – no one would have the surname Falsani.
 Once again, a fictitious name – no one has two surnames.
 Oddly enough, there really is a vehicle by this name made by Isuzu.
The Escalade is, of course, a vehicle only slightly smaller then the state of Rhode Island
 Lack of memory seems to be a trait with persons with names like Falsani. They particularly have difficulty remembering where they put their wallet when the dinner/bar bill arrives.
 The author gratefully acknowledges the assistance of Roger Burgmeier in the preparation of this article.
[a] Peter Riley is a graduate of Williams College and the University of Minnesota Law School. Peter is a shareholder in the Minneapolis law firm of Schwebel, Goetz & Sieben, P.A. Peter’s practice is limited to the representation of victims of negligence, products liability and medical malpractice. He was a member of the Minnesota Supreme Court Standing Committee on No-Fault from 1991 – 97. Peter is Vice President of the MTLA; he serves on their Executive Committee, and chairs the MTLA Trial PAC and Affinity Programs Committees.