Beginning in 1998, Mack engines began using an electronic control system known as the V-MAC III. Late model Mack engines are controlled by the V-MAC IV. These systems include two modules: A VECU (Vehicle Electronic Control Unit) and EECU (Engine Electronic Control Unit).
V-MAC III and IV contain two stored "Incidents." The event threshold for these Incidents to be recorded is normally a decrease in wheel speed of 10 miles per hour per second, but this threshold can be changed at the customer's request. In addition, Incidents are recorded when the engine speed increases rapidly.
In late model V-MAC IV systems, the stored events represent one braking incident and the last stop of the vehicle. In some cases, the parking brake must be applied in order for the last stop to be recorded.
Mack Incidents record event data for approximately 16 seconds before the Incident and 16 seconds after the Incident. Early V-MAC III modules report data in 0.5 second increments. Most V-MAC III systems report data in two-tenths-of-a-second (0.2 seconds) intervals, and speed is reported to the nearest whole mile per hour. V-MAC IV sysems report data in 0.25 second intervals.
Mack Incident Reports include wheel speed, engine speed, and the status of up to eight “switches.” Usually among these switches are cruise control (on/off), service brake (on/off), and key switch (on/off).
It is important to note that Mack Trucks have not provided public access to their Incident Data. Mack ECUs must be physically removed from the truck and sent to one of two Third Party Authorized Providers. Contact information for the two firms authorized by Mack to perform data extraction is below. The cost of this service is approximately $2,250. The service that is provided for this fee is the controlled extraction of the data.
Individuals or companies requiring incident data extraction should contact:
Mr. Tim Cheek, PE
Delta[V] Forensic Engineers
Mr. John Steiner
|© Heavy Truck EDR | Disclaimer||Messerschmidt Safety Consultants | Bloomberg Consulting | Armstrong Forensic Engineers | Yosko Consulting|