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Fleet Parameter Variables

There are many fleet parameter variables that can affect ECM data. All are not covered in this RP. The most important fleet parameters or "inputs" affecting ECM data are:

Pulses per mile is defined as the number of electronic pulses sent to the ECM during a mile of operation. "Pulses per mile" is one of the trucking industry's most abused settings, and can be deliberately set improperly to change maximum vehicle speed. Having the wrong pulse-per-mile count is a common source of bad ECM data, yielding inaccurate comparisons of fuel use, average speed and other data.

KEY FACTORS THAT AFFECT ENGINE ECM DATA RELIABILITY

There are many issues affecting engine ECM data accuracy that fleet managers must understand when using ECM data to make business decisions. The most important issues are:
  1. There are many fleet-specified parameters to program correctly.
  2. There are many variables to consider and understand when analyzing ECM data.
  3. There are no standards for data collection or calculation methods. ECM data gathering and calculation methods vary significantly among engine models from a single manufacturer; they vary even more significantly among engine manufacturers themselves.
  4. ECMs create data sets with varying degrees of accuracy. Accuracy of fuel measurement, mileage, and other parameters varies greatly. Errors of up to 10 percent are not unusual.
  5. Fleet managers must invest a significant amount of time to ensure ECM data accuracy.
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