Fleet maintenance glossary

Plain definitions of the terms fleet managers run into, with the rule behind each one where there is one.

Annual inspection

Another name for the periodic inspection every commercial motor vehicle has to pass at least once every 12 months under 49 CFR 396.17. More ›

Appendix A to Part 396

The minimum standards a periodic, or annual, inspection has to cover under 49 CFR 396.17.

CDL

Commercial driver's license: the license a driver needs to operate the heavier commercial vehicles covered by 49 CFR Part 383.

CDL endorsements

Letters added to a CDL for certain vehicles or loads: H for hazardous materials, N for tank vehicles, P for passengers, S for school buses, T for double or triple trailers, and X for tank vehicles carrying hazardous materials.

CMV

Commercial motor vehicle: a vehicle used in commerce that meets the weight, passenger or hazardous materials thresholds defined in 49 CFR 390.5.

DQ file

Driver qualification file: the record a carrier keeps for each driver under 49 CFR 391.51, from the employment application to the medical certificate. More ›

DVIR

Driver vehicle inspection report: the driver's written report on a vehicle's condition at the end of the day's work, under 49 CFR 396.11. More ›

ELD

Electronic logging device: a device that records a driver's hours of service.

Engine hours

The total time an engine has run. Trucks that idle a lot add engine hours faster than miles, so some services are set by hours.

FMCSA

Federal Motor Carrier Safety Administration: the federal agency that writes and enforces the motor carrier safety regulations.

GVWR

Gross vehicle weight rating: the maximum loaded weight the manufacturer rates a vehicle for.

Medical examiner's certificate

The driver's medical card, issued after a DOT physical. Drivers need an exam at least every 24 months, and some every 12 months, under 49 CFR 391.45. More ›

MVR

Motor vehicle record: a driver's driving record from a state licensing agency. Carriers pull one at hiring and at least every 12 months under 49 CFR 391.23 and 391.25.

Periodic inspection

The DOT annual inspection. Every commercial motor vehicle, and each vehicle in a combination, has to pass one at least once every 12 months under 49 CFR 396.17. More ›

PM

Preventive maintenance: scheduled service done before parts fail, set by miles, engine hours or months. More ›

PM-A, PM-B, PM-C

Common shop names for levels of preventive maintenance, from the frequent, lighter service (A) to the bigger service at the long interval (C). They aren't federal terms, and what each covers varies by shop.

Post-trip inspection

The end-of-day inspection that produces the DVIR.

Pre-trip inspection

The driver's check before driving. Under 49 CFR 396.13 the driver must be satisfied the vehicle is safe, review the last DVIR when one was required, and sign it. More ›

Reorder point

The stock level at which you order more of a part.

Repair certification

The carrier's sign-off on a DVIR that a defect was repaired, or that repair is unnecessary, before the vehicle is driven again, under 49 CFR 396.11(a)(3).

Service interval

How often a service comes due, in miles, engine hours or months.

Telematics

Devices that send a vehicle's location and engine data, such as GPS trackers.

Work order

The record of a repair or service job: the vehicle, the work done, the parts, who did it and when.