haulrecordFMCSA data

Violation codes / 393.43DBMA

49 CFR 393 · Parts and accessories

393.43DBMA

What it means

Brake - Breakaway not attached to the towing vehicle

What the rule actually says

This violation cites 49 CFR 393.43, breakaway and emergency braking. The regulation reads:

(a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped with a means for providing that in the case of a breakaway of the trailer, the service brakes on the towing vehicle will be capable of stopping the towing vehicle. For air braked towing units, the tractor protection valve or similar device shall operate automatically when the air pressure on the towing vehicle is between 138 kPa and 310 kPa (20 psi and 45 psi).

(b) Emergency brake requirements, air brakes. Every truck or truck tractor equipped with air brakes, when used for towing other vehic…

The section continues.

49 CFR 393.43, Breakaway and emergency braking. Read the full section on eCFR

Quoted verbatim from the Electronic Code of Federal Regulations. Nothing here is a paraphrase, and nothing here is legal advice on a citation.

Times recorded27,6436% as often as 393.9, the most cited
How common121stof the 200 most cited codes, out of 2,372 that exist
Regulation393.43Parts and accessories

How often this comes up

This violation was recorded 27,643 times across the roadside inspections in the FMCSA file, making it the 121st most frequently cited code. Whether a given instance puts a vehicle or driver out of service is decided at the roadside by the inspector, not by the code itself, so the same violation can end a trip or simply be noted.

It sits under 49 CFR Part 393, which covers parts and accessories. To see it in context, look up a carrier and read its inspection history: the same code appearing repeatedly is a different signal from a single occurrence.

Look up a carrier's inspection record

Other parts and accessories violations

Counts are from the FMCSA Inspections and Violations file via data.transportation.gov. This describes how the violation is recorded, and is not legal advice on a citation.