What does a 393.48B1 citation mean? Will it ground your truck? Get evidence-backed answers from 13M+ inspection records.
Ranks #1,686 of 3,146 FMCSR codes by citation frequency • OOS rate of 2.2% is below the FMCSR-wide average of 33.3%.
Defective brake limiting device
Direct answers grounded in TruckCodex inspection data
No, this citation almost never results in an out-of-service order. Across our inspection records, 393.48B1 has a 2.3% out-of-service rate—far below the 31.4% national average for all FMCSR violations. Out of 43 all-time citations for this code, only 1 truck was placed out of service. You can typically continue operating while you schedule the repair.
It's a low-severity citation. The 2.3% OOS rate for 393.48B1 is dramatically lower than peer codes in vehicle maintenance. For comparison, general brake inspection violations (396.3a1) have a 45.3% OOS rate, and inoperable lamps (393.9) sit at 6.9%. Our data shows this defect is treated as a maintenance item, not an immediate safety shutdown.
First, get the brake limiting device inspected by a qualified mechanic. In the last 90 days, 393.48B1 co-occurs with brake tubing defects, steering wear, and coupling issues in the same inspections—so a full brake system check is smart. Document the repair work and keep records. Since only 1 in 43 citations resulted in an OOS order, you have time to fix it properly rather than rushing.
Citations have been inconsistent over the last 12 months. Our records show 29 citations in the past year, with a spike in September 2025 (7 citations) and March 2026 (5 citations). Most months had 1–5 citations. The recent trend doesn't suggest a rising enforcement wave—these appear to be scattered findings tied to routine inspections rather than a coordinated crackdown.
Texas dominates the enforcement data, with 15 citations over the last 180 days—accounting for the majority of national citations for this code. That 15-citation cluster also had 1 out-of-service order, giving Texas a 6.7% OOS rate for this violation. If you operate in Texas, brake limiting device inspections should be part of your routine maintenance audit.
Freightliners lead the list with 13 citations all-time, followed by Kenworths with 9 citations. Internationals, trailers, and other heavy-duty makes make up the rest. Our data shows this is not isolated to one manufacturer—it spans the standard heavy truck fleet. Regardless of your truck's make, proper brake limiting device maintenance is essential.
Yes, you can submit a DataQs (Roadside Inspections Records) dispute if you believe the citation is inaccurate. The process depends on whether the inspector's finding was a documentation error or an actual equipment defect. If the brake limiting device was functioning and the inspector misidentified it as defective, document that with photos and service records. FMCSA reviews equipment challenges differently than paperwork errors, so be specific about what was wrong with their finding.
The FMCSA assigns points based on severity weight, which is not available in our citation data. However, 393.48B1 falls under the Vehicle Maintenance safety category. Points are calculated by FMCSA's CSA algorithm and weighted by the violation's relative severity and your carrier's BASIC scores. Contact your carrier's safety manager or check your CSA profile directly—they can tell you the exact point impact within 48 hours of the citation.
Where 393.48B1 is most commonly cited (last 180 days)
Other violations commonly found on the same inspection (last 90 days)
TruckCodex aggregates official public-sector datasets. See the Source registry for dataset-level coverage and the Freshness log for last-import timestamps.
Census, SAFER, SMS, Licensing & Insurance (L&I), roadside inspections, crashes, and authority history.
Vehicle recall campaigns, defect investigations, and consumer safety complaints (SCRS).
Cross-border carrier registry and Canadian recall campaigns where applicable.
TruckCodex is an independent aggregator; it is not affiliated with FMCSA, NHTSA, EIA, or Transport Canada. Always verify compliance-critical information directly with the originating agency.