393.48A

393.48A Violation: Inoperative or Defective Brakes

A required brake was recorded as inoperative or unable to perform as required.

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Plain-English answer

What does violation code 393.48A mean?

A required brake was recorded as inoperative or unable to perform as required.

Why carriers pay attention

How 393.48A can affect a trucking safety record

An inoperative brake can be individually serious and may also count toward a 20-percent defective-brake out-of-service calculation. The cited component and wheel position must be precise.

FMCSA inspection data can flow into the Safety Measurement System used to organize carrier performance into Behavior Analysis and Safety Improvement Categories, commonly called FMCSA SMS BASICs. The carrier should verify the inspection, the assigned BASIC, and whether the violation is included in the official calculation.

How it gets cited

Common 393.48A inspection situations

  • A service brake does not apply, release, or produce braking force as expected.

  • The inspection report combines a component defect with a conclusion that the brake was inoperative.

DataQ review

When a 393.48A violation may deserve a closer look

A DataQ challenge should identify a specific factual or legal error in the inspection data. These are review questions—not assumptions that the violation should be removed.

Potential review angles

  • The brake operated and the report misidentified the defective component or wheel end.
  • The cited condition did not make the brake inoperative under the applicable standard.
  • The vehicle or trailer unit was incorrectly attributed to the carrier.

Evidence to collect

  • Brake test results recorded at or immediately after inspection
  • Technician diagnosis identifying the actual component condition
  • Vehicle, trailer, and wheel-position photographs
Compliance expert review

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DataQs changes in 2026

A stronger review process still requires a stronger record.

FMCSA’s 2026 DataQs overhaul adds independent review stages, decision deadlines, and more detailed explanations. Carriers still carry the burden of identifying the error and supporting the requested correction.

See the 2026 DataQs changes
Frequently asked questions

393.48A violation FAQ

What does a 393.48A violation mean?

A required brake was recorded as inoperative or unable to perform as required.

Which FMCSA SMS BASIC is associated with 393.48A?

Code 393.48A is commonly associated with the Vehicle Maintenance BASIC in the FMCSA Safety Measurement System. Inclusion and weighting should be confirmed on the carrier’s official record.

Can a trucking company challenge a 393.48A violation?

A carrier may submit an FMCSA DataQs Request for Data Review when the underlying inspection data is incomplete or incorrect. A repair made after the inspection does not by itself prove the original 393.48A finding was wrong.

What evidence helps review a 393.48A violation?

Useful evidence may include brake test results recorded at or immediately after inspection, technician diagnosis identifying the actual component condition, vehicle, trailer, and wheel-position photographs. The best evidence is tied to the cited vehicle, driver, location, and inspection time.

Keep reviewing

Related DOT violation codes

View all violation guides
393.47EBrake Out of AdjustmentBrakes396.3A1BOS20 Percent or More Defective BrakesBrakes393.45B2Brake Hose Chafing or KinkingBrakes393.9Inoperable Required LampLighting

Source references: 49 CFR 393.48 and FMCSA roadside inspection data. This guide is general information and does not guarantee a DataQs outcome or replace legal advice.