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Networkcar Identifies Most Common Vehicle Diagnostic Trouble Codes

SAN DIEGO – Networkcar has analyzed diagnostic trouble codes (DTC) gathered from thousands of commercial vehicles across the United States that use its Networkfleet wireless vehicle management system.

by Staff
December 4, 2006
2 min to read


SAN DIEGO – Networkcar has analyzed diagnostic trouble codes (DTC) gathered from thousands of commercial vehicles across the United States that use its Networkfleet wireless vehicle management system.

Networkfleet continuously monitors and collects data directly from a vehicle’s engine computer and from a global positioning system (GPS). An analysis of aggregate Networkfleet data shows that 47 percent of diagnostic trouble codes for light-/medium-duty (OBD-II) vehicles were related to emissions issues, and 24 percent were related to fuel consumption issues.

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The Networkfleet system consists of an in-vehicle unit that wirelessly transmits diagnostic and GPS data. Fleet managers access a Web-based application to view specific vehicle data, such as current location, fuel consumption, mileage, speed, and idle time. Networkfleet automatically notifies fleet managers by e-mail immediately when a vehicle reports a diagnostic trouble code (DTC). Networkfleet provides the precise DTC code and a description identifying the specific nature of the problem. This allows technicians to procure parts ahead of time and begin working on the problem immediately instead of spending time trying to determine what is wrong.

Each month, Networkfleet intercepts 30,000 to 40,000 DTC codes from thousands of vehicles in fleets across the United States. The top three individual diagnostic trouble codes collected by Networkfleet include:


  • Light Vehicle DTC (P0300) is related to cylinder misfires. Misfires can be indicative of poor maintenance or of a faulty or worn ignition system.

  • Light Vehicle DTC (P0171) indicates that the air to fuel mixture is suboptimal. This could be indicative of a faulty O2 sensor or a faulty/worn fuel pump.

  • Light Vehicle DTC (P0420) indicates that there may be a problem with the vehicle catalyst and that it should probably be replaced.

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