Electronic control modules (ECM) on today's heavy trucks can provide a wealth of information to the attorneys.
They can also provide no information, useless information or erroneous information.
Knowing something about the way they work and how they may help or hurt your case is becoming increasingly important in trucking cases.
ECMs are know by many other names but essential all of the units perform the same sort of functions, which is to monitor the engine function and related systems.
ECM units are connected to several sensors and sending units on the engine and other systems.
In general these units may provide information concerning fuel consumption and efficiency, braking, mileage, speed, and maintenance issues.
They are also used to supervise a motor carrier's fleet and the behavior of individual drivers.
The North American Transportation Management Institute publication Motor Fleet Safety Supervision, Principles and Practices encourages the use of recoding devices to help monitor driver, vehicle and operations.
ECM systems vary, by manufacturer and are truly product specific applications.
There is little standardization in the industry, and it will require proprietary software to download the ECM data and produce a usable report.
Fortunately, most trucking cases do not involve legal actions against the engine manufacturer and thus it is possible to obtain this software from the engine manufacturer, or their ECM related vendor.
The ECM might tell you if the driver was speeding, or if the driver braked, or might show the driver's logs are a sham, but maybe it won't.
ECM's may contain information from other data devices it receives information from including sensors such as the ABS brake and automatic transmission control units.
The type of information you may expect to obtain includes diagnostic data, trip data, event data, audit data, maintenance data, and configuration data.
Of most use is the event data which may yield useful information to be used in accident reconstruction.
The ECM also produces output based upon the inputs that control or assists in the vehicles function.
Finally ECM's share information with end users by reporting stored information in usable formats based upon mathematical algorithms and data.
Generally, the data is stored two ways: temporary and permanent memory.
In temporary memory data is stored in a buffer where new data overwrites old data.
The length of time recorded varies by manufacturer and model, but usually ranges from seconds to a few minutes.
Permanent memory information that is stored in the unit accumulates over time.
Some of this information is processed information, which is to say it is accumulated, and processed to store outputs such as total miles driven, and maximum speed.
Permanent memory also stores critical event data if certain pre-set criteria are met.
For example, a common pre-set is for hard braking, is a decline in speed of anywhere between 7 to 12 mph.
This input will cause the event data to be automatically moved to permanent memory.
Even where such data is not moved to permanent memory, it may still exist in the memory buffer.
To the extent that it does, it can be lost if the conditions that allow new data to overwrite old exists.
A vehicle that is operated post accident may destroy evidence of the event, thus precautions must be taken to preserve this evidence.
Keep in mind ASTM Standard E 860, Standard Practice for Examining and Preparing Items That Are or May Become Involved in Criminal or Civil Litigation, 2007.
You should put other interested parties on notice of any inspection and take precautions to preserve evidence.
Obviously you will need an expert to obtain the data on the ECM.
Make sure that your expert has the correct software and expertise to correctly download the ECM.
Without proper precautions, simply establishing a data connection to a powered ECM can result in data loss.
It is important that you insure that your expert also does a complete vehicle inspection, and verify the condition of the vehicle is the same as at the time of the crash.
Items of importance include the axle's size, tire size and tire condition.
It is also necessary to determine the profile in the ECM related to this equipment.
The ECM is set for factory tires and axles when it leaves the manufactures control.
If your expert assumes the data is accurate without checking the profile you may end up with a big bill and a discredited expert opinion.
Once you have recovered the data and you may run into a common problem in that the data is reported as a single trip.
In other words, the user never set the software up and the basic factory setting was in single trip mode; now what? If the case is worth it, there are ways to uncover the data you're looking for.
By now most people are familiar with the fact that they can erase their computer hard drive, yet computer savvy wizards can reconstruct long ago erased files.
The same is true for ECM data.
If you have a single trip report for the life of the truck, you can still parse the data and force the data into more usable parts if you can identify markers in the data.
This is not possible every time, but in significant cases consulting with a software engineer with expertise in ECM systems may lead to useful information recovery.
In order to perform such a recover you will need the original ECM, and exemplars to experiment.
Exemplars from the field must be obtained to be experimented on.
It is important to note that attempting to retrieve the data in this manner will most likely alter or even destroy the data on the ECM so a propriety software data download should have already been secured, and electronic and paper copies provided to all parties.
This should also be done only with court approval to avoid spoliation claims.
ECM data may provide information, but is it reliable? Unfortunately, there is no direct answer to this question because it largely depends on the system employed, the method of calculation and the data.
However, the idea that something is recorded and reported by a computer monitoring system gives it an air of scientific validity that can overstate the actual reliability of the results.
There are known variables and places for inaccuracies to crop up in almost every part of ECM data, particularly if you do not understand how it is calculated.
Common errors include incomplete or missing data, errors in reported values such as speed, breaking, acceleration, and engine governor.
Speed errors can arise from the source of there input or from calibration errors.
For instance if the speed data is based upon a mathematical calculation on data from the power train, changes in the transmission, wheel, or weight may affect the calculation and thus reported data.
Studies have shown that significant under reporting of speed in hard braking maneuvers in ABS equipped tractors.
If maintenance has changes the tire or axle size, then the reported speed is going to be wrong.
If wear has significantly eroded the tread speed results are affected.
Finally if the ECM profile regarding speed was changed when the tire size was changed it must be set correctly or the results can have error induced not only by the tire size change but also by the ECM profile.
Speed is calculated by the ECM using numerical values from known factors such as tire revolutions per mile, axle ratio and drive shaft revolutions.
The ECM calibration for these factors is set before sale, but can be altered with software after sale.
ECM and other data recorders are not silver bullets, but rather just one more piece of the puzzle.
The idea that they are black boxes which will answer our questions confuses the science with the magic 8 ball.
If you and a good expert understand the collision, the truck, its equipment, the software, and related profiles you may develop some very useful information that may prove your clients case.
Make sure you understand all of these things before you pay for an ECM download, or you are just wasting money.
They can also provide no information, useless information or erroneous information.
Knowing something about the way they work and how they may help or hurt your case is becoming increasingly important in trucking cases.
ECMs are know by many other names but essential all of the units perform the same sort of functions, which is to monitor the engine function and related systems.
ECM units are connected to several sensors and sending units on the engine and other systems.
In general these units may provide information concerning fuel consumption and efficiency, braking, mileage, speed, and maintenance issues.
They are also used to supervise a motor carrier's fleet and the behavior of individual drivers.
The North American Transportation Management Institute publication Motor Fleet Safety Supervision, Principles and Practices encourages the use of recoding devices to help monitor driver, vehicle and operations.
ECM systems vary, by manufacturer and are truly product specific applications.
There is little standardization in the industry, and it will require proprietary software to download the ECM data and produce a usable report.
Fortunately, most trucking cases do not involve legal actions against the engine manufacturer and thus it is possible to obtain this software from the engine manufacturer, or their ECM related vendor.
The ECM might tell you if the driver was speeding, or if the driver braked, or might show the driver's logs are a sham, but maybe it won't.
ECM's may contain information from other data devices it receives information from including sensors such as the ABS brake and automatic transmission control units.
The type of information you may expect to obtain includes diagnostic data, trip data, event data, audit data, maintenance data, and configuration data.
Of most use is the event data which may yield useful information to be used in accident reconstruction.
The ECM also produces output based upon the inputs that control or assists in the vehicles function.
Finally ECM's share information with end users by reporting stored information in usable formats based upon mathematical algorithms and data.
Generally, the data is stored two ways: temporary and permanent memory.
In temporary memory data is stored in a buffer where new data overwrites old data.
The length of time recorded varies by manufacturer and model, but usually ranges from seconds to a few minutes.
Permanent memory information that is stored in the unit accumulates over time.
Some of this information is processed information, which is to say it is accumulated, and processed to store outputs such as total miles driven, and maximum speed.
Permanent memory also stores critical event data if certain pre-set criteria are met.
For example, a common pre-set is for hard braking, is a decline in speed of anywhere between 7 to 12 mph.
This input will cause the event data to be automatically moved to permanent memory.
Even where such data is not moved to permanent memory, it may still exist in the memory buffer.
To the extent that it does, it can be lost if the conditions that allow new data to overwrite old exists.
A vehicle that is operated post accident may destroy evidence of the event, thus precautions must be taken to preserve this evidence.
Keep in mind ASTM Standard E 860, Standard Practice for Examining and Preparing Items That Are or May Become Involved in Criminal or Civil Litigation, 2007.
You should put other interested parties on notice of any inspection and take precautions to preserve evidence.
Obviously you will need an expert to obtain the data on the ECM.
Make sure that your expert has the correct software and expertise to correctly download the ECM.
Without proper precautions, simply establishing a data connection to a powered ECM can result in data loss.
It is important that you insure that your expert also does a complete vehicle inspection, and verify the condition of the vehicle is the same as at the time of the crash.
Items of importance include the axle's size, tire size and tire condition.
It is also necessary to determine the profile in the ECM related to this equipment.
The ECM is set for factory tires and axles when it leaves the manufactures control.
If your expert assumes the data is accurate without checking the profile you may end up with a big bill and a discredited expert opinion.
Once you have recovered the data and you may run into a common problem in that the data is reported as a single trip.
In other words, the user never set the software up and the basic factory setting was in single trip mode; now what? If the case is worth it, there are ways to uncover the data you're looking for.
By now most people are familiar with the fact that they can erase their computer hard drive, yet computer savvy wizards can reconstruct long ago erased files.
The same is true for ECM data.
If you have a single trip report for the life of the truck, you can still parse the data and force the data into more usable parts if you can identify markers in the data.
This is not possible every time, but in significant cases consulting with a software engineer with expertise in ECM systems may lead to useful information recovery.
In order to perform such a recover you will need the original ECM, and exemplars to experiment.
Exemplars from the field must be obtained to be experimented on.
It is important to note that attempting to retrieve the data in this manner will most likely alter or even destroy the data on the ECM so a propriety software data download should have already been secured, and electronic and paper copies provided to all parties.
This should also be done only with court approval to avoid spoliation claims.
ECM data may provide information, but is it reliable? Unfortunately, there is no direct answer to this question because it largely depends on the system employed, the method of calculation and the data.
However, the idea that something is recorded and reported by a computer monitoring system gives it an air of scientific validity that can overstate the actual reliability of the results.
There are known variables and places for inaccuracies to crop up in almost every part of ECM data, particularly if you do not understand how it is calculated.
Common errors include incomplete or missing data, errors in reported values such as speed, breaking, acceleration, and engine governor.
Speed errors can arise from the source of there input or from calibration errors.
For instance if the speed data is based upon a mathematical calculation on data from the power train, changes in the transmission, wheel, or weight may affect the calculation and thus reported data.
Studies have shown that significant under reporting of speed in hard braking maneuvers in ABS equipped tractors.
If maintenance has changes the tire or axle size, then the reported speed is going to be wrong.
If wear has significantly eroded the tread speed results are affected.
Finally if the ECM profile regarding speed was changed when the tire size was changed it must be set correctly or the results can have error induced not only by the tire size change but also by the ECM profile.
Speed is calculated by the ECM using numerical values from known factors such as tire revolutions per mile, axle ratio and drive shaft revolutions.
The ECM calibration for these factors is set before sale, but can be altered with software after sale.
ECM and other data recorders are not silver bullets, but rather just one more piece of the puzzle.
The idea that they are black boxes which will answer our questions confuses the science with the magic 8 ball.
If you and a good expert understand the collision, the truck, its equipment, the software, and related profiles you may develop some very useful information that may prove your clients case.
Make sure you understand all of these things before you pay for an ECM download, or you are just wasting money.
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