“Black Boxes” on Heavy Trucks, What Are They and How Do I Get It?

May 8, 2021

Event Data Recorder (EDR) or “Black Box” data as it is generally referred to is quite different that those found on passenger cars. The data that is available is not actually designed as an EDR, like those in passenger vehicles. For the most part, we get EDR data on heavy trucks as a function of interpreting data a mechanic would collect to find out how a truck has been performing, analyzing how a driver has been driving, or a “snapshot” of an event around a “trouble code” to help them know how to fix a problem. Although It is not designed for an EDR, with validation it can be an extremely valuable source of information on a collision involving a heavy truck.

In this article, I will share the comparison between passenger car and heavy truck EDR’s, data available in heavy trucks found in North America, and how this data can be retrieved. This is by no means an exhaustive source, and you will need to seek out training if testifying to the data. In future articles, I will go over validation testing specific to engine or ECU types.

Comparison to Passenger Car EDR’s:

Generally, passenger car EDR’s come from the Airbag Control Module (ACM), which is a sensor that collects information on speed, rpm, seatbelt usage, and acceleration (among many other) to make the determination on when to deploy airbags. If your vehicle experiences a change in velocity, the ACM makes the decision on whether or not you need the airbags to protect the occupants. It classifies these events as “deployment” or “non-deployment”. When it writes one of these events to the memory, it records several seconds of speed, rpm, braking, etc. prior to the event and most will record the severity of the crash pulse or delta-v.

Example of Passenger Car EDR Data:

Heavy Trucks on the other hand, are not linked to an airbag system. In the early days of truck EDR’s, the potential for data came from the Engine Control Module (ECM). The types of data available varies greatly by the engine type, and not make of truck. You can have many different engines in each make of truck. For instance, a 2020 Peterbilt may have a Paccar or Cummins Engine. Each engine make give very different data. Cummins engines are pretty reliable on giving data if the driver made a hard brake application before or after the crash, and power was not lost but a 2020 Paccar may only give data when a fault code was triggered.

Variations of Engines Available by Make

There are many different variations of engines available by truck make. See the following chart for engine combinations by make:

There are three main types of triggers that can write data: hard brake, snapshot and last stop.

· Hard Brake: There are different terms for this type of event by engine make. Some call it Fast Stop, Quick Stop, or Acceleration Trigger, but for the most part the vehicle speed has to change by a pre-programmed threshold that varies from 7-10 mph per second. Once the truck reaches this threshold, an event will be written to memory. This event will be stored until overwritten by consecutive hard brake events. Depending on the engine make this can be 2 or more. It is important that the truck does not go back into service before this data is extracted.

· Snapshot: This type of event is triggered by a diagnostic trouble code (DTC). This can be from your truck losing all coolant in the collision and the DTC is triggered to notify the driver of an operating truck that there is a problem, then give the mechanic that is diagnosing the issue an idea of what was occurring when the DTC was triggered. For crash investigations, this is important because sometimes, you can get several seconds of speed surrounding the snapshot. This means, you may be able to determine what the speed was prior to a collision.

· Last Stop: If a truck records a Last Stop event, it will record several seconds of data prior to the vehicle speed reaching zero. For example, with Detroit Diesels this can be up to 144 seconds. In theory, you will always have EDR data on a truck that records a Last Stop until it starts moving again. The problem is efforts by first responders to open a roadway cause the driver to move the vehicle from the roadway. Or the driver may be released and drive the truck from the scene, or the truck is towed away without removing the driveshaft. When this happens, the Last Stop related to the crash is erased and a new Last Stop event will be created when the truck stops moving again.

Accessing the data from heavy trucks:

To access this data, you have a couple of options:

First, you can use OEM software and an RP1210 interface such as Nexiq, Dearborn DPA, Noregon, etc. Using OEM software can be tricky if you are not familiar with it, and this is discouraged unless you have extensive training and experience as you can set new fault codes or erase data. This gives you possibly hundreds of pages of data to comb through to find your crash data.

Second, DG Technologies owns and produces the Synercon Technologies line of forensic data extraction tools. The Forensic Link Adapter (FLA) is a forensically sound interface that has its own on-board RP1210. If an engine is supported with TruckCrypt software, this extraction is a simple as following prompts on screen and pushing one of two buttons. You then upload the data to a portal, which populates a user-friendly report in a standardized format.

Engines supported by Synercon:

***Maxforce engines by Navistar (International) is not listed, but are also supported

Example of TruckCrypt Report:

In addition to engine data, there are other modules on a truck that can give crash data. These can include collision avoidance systems, camera systems, braking systems, or fleet telematics. When you have this type of case, seek out a qualified expert who deals with truck crash investigations regularly and is up to date on training. This is a constantly evolving field.

If you need training on Heavy Truck Event Data Recorders, James Loftis offers training through the Forensic Training Group several times per year. Visit their site at Also check out other training opportunities in Commercial Motor Vehicle investigations.

If you need an expert or consultant on this or other Commercial Motor Vehicle related topics, contact Sooner Crash Consulting at (918)837-1935, email or visit our website,

Finding the Right Expert in Commercial Motor Vehicle Collisions:

April 26, 2021

Commercial Motor Vehicle, or heavy truck cases are extremely complex and require a level of expertise that is unique only to CMV collisions. When choosing an expert, it is not a one size fits all situation. Whether using a reconstructionist or engineer, you want to ensure they have the proper training and experience in these types of investigations.

Digital evidence can also be short-lived. You want to ensure you get your expert involved quickly, as well as take the proper steps to preserve any potential data.

In this post, we will discuss some basic items to consider when preserving evidence, as well as what to look for in an expert.

1. Time is of the essence. Secure data!!!

The newer trucks on the road have a ton of possibilities for having event data recorder (or black box) information. In the early days of truck event data recorders, the only information available came from a select few engines that had data on their engine control modules. For many years this remained true, but that is no longer the case. Now trucks have many different electronic control units, and even telematic devices which can give information related to your collision. In addition, many late model trucks have collision avoidance devices that can also give data on your collision and tell you if the driver or the truck applied brakes or intervention methods to avoid a crash.

Electronic logs can give historical data for many days prior to the collision. They also can trigger a “critical event” that surrounds a collision. You must be specific when asking for this data.

Many new trucks also have either a factory installed camera system, or an aftermarket system that can take still photos or video of a critical event. Some of these cameras may work in conjunction with collision avoidance systems and the driver or company may not even be aware of them on the truck.

And in the end, do not forget the basics. Heavy trucks are a strictly regulated industry, for reason. This is because of their size, weight, and potential for injury and damage if not operating properly. The Commercial Vehicle Safety Alliance’s three-day International Roadcheck event in 2020, resulted in an overall vehicle out-of-service rate of 20.9% in North America.

You may only get one chance to inspect the vehicle. Many times, trucks can be repaired and put back in service when passenger cars in the same collision will be totaled. If a brake problem or other defect contributed to the crash, this evidence is also short-lived. You need to make sure you have a qualified expert who conducts regular post-crash inspections on trucks and is also familiar with the federal regulations related to the trucking industry.

2. Choosing the right expert.

Many engineers and reconstructionist say they can handle a heavy truck collision the same as any other collision. You need an expert who specializes in heavy truck collisions for the same reason you wouldn’t go to a podiatrist when having heart problems. Sure, anyone who goes through the basic collision reconstruction training series will get a lecture on commercial motor vehicle collisions… Maybe they even went to a 40- or 80-hour course on CMV crash investigations. But have they ever investigated and testified in CMV collision cases? Have they done research on the validity of methods used? Do they have a CDL, or ever driven a truck?

You want to do your homework before hiring the wrong person.

Take these three main points into account when selecting an expert:

a. Is my expert qualified?

Have they been trained specifically on Commercial Motor Vehicle collisions? Many different training organizations offer training specific to CMV’s and heavy trucks. Technology is constantly evolving. Even if they have been trained, how often do they retrain, or go to conferences specific to CMV crash investigation/reconstruction.

b. Is my expert equipped?

Handling CMV collisions are a costly business. You must have expensive equipment to access event data recorders. Often this cannot be done through the diagnostic port, and the module has to be interrogated off of the truck. If your expert cannot provide this service in-house, this adds time and expense to your case.

Special tools are required to inspect brakes, and plumb into damaged air lines/tanks if the truck sustained heavy damage. Scales are needed to get axle weights to calculate brake force, and total weight of the truck is needed for momentum or kinetic energy calculations. If your expert does not have access to scales, they are probably using published data. While this may get you close, you will want to narrow down results by getting accurate data.

c. Can my expert communicate with a jury/judge?

This may be the most important of these three points. Can your expert communicate well, and does he come off as genuine and honest? They may be the most knowledgeable person in the room on CMV collisions, but if they cannot explain them on the simplest terms so everyone can understand, you have just waisted time and money.

We at Sooner Crash Consulting and Reconstruction specialize in Commercial Motor Vehicle/Heavy Truck collisions. James Loftis is a nationally recognized expert in CMV collisions and frequently instructs police officers, reconstrutionists and engineers on CMV collision reconstruction. He has often lectures at conferences across the United States on CMV collisions and Heavy Truck Event Data Recorders. He conducts validation testing on Heavy Truck Event Data Recorders many times per year.

We are fully equipped to handle your Commercial Motor Vehicle collision investigation needs or can assist your local reconstructionist or engineer in their investigation.

Give us a call, or email today at (918)837-1935 or