TOPICS

History and Background

Event Data Recorders (EDRs) in passenger cars (primarily in the Airbag Control Module) have attracted a great deal of media interest over the past several years. Comparatively speaking, much less attention has been paid to EDRs in heavy trucks and commercial motor vehicles (CMVs).

Beginning in 1993, the Environmental Protection Agency tightened emissions requirements for diesel engines in CMVs. In response, engine manufacturers began using electronic (i.e., computerized) engine control units. These computers enhanced the precision of injector timing, the fuel/air mix, and other mechanical factors, creating more efficient and cleaner engines.

As computer hardware prices dropped, design engineers could incorporate more features into these Engine Control Modules (ECMs). ECMs then began to monitor data that were of interest to logistics, safety, and maintenance professionals. By 1995, most ECMs monitored data such as fuel economy, time at idle, active fault codes (problems in the engine), and the amount of time that a truck spent in various speed bands, including how often it exceeded a pre-set maximum-tolerable speed.

« Previous Topic | Next Topic »