Direct answers on 393.52(a) enforcement, out-of-service risk, and what drivers need to do after citation. Based on 68 all-time violations in our database.
Ranks #1,558 of 3,146 FMCSR codes by citation frequency • OOS rate of 100.0% is above the FMCSR-wide average of 33.3%.
Direct answers grounded in TruckCodex inspection data
Yes. Across our inspection records, every single citation for 393.52(a) resulted in an out-of-service placement—a 100.0% OOS rate. This is far higher than the 31.4% average OOS rate across all FMCSR codes. Once cited, you cannot legally operate that vehicle until the violation is corrected and re-inspected. Do not attempt to drive.
This code ranks #1534 out of 3,036 FMCSR codes by citation volume, making it relatively uncommon. However, its enforcement severity is extreme: the 100.0% OOS rate far exceeds peer violations like 393.9(a) (15.4% OOS), 393.11 (1.8% OOS), and 393.78 (0.3% OOS). When 393.52(a) is cited, enforcement is absolute—there is no discretion for minor non-compliance.
Our inspection records show zero citations for 393.52(a) in the last 90 days and zero in the last 12 months. All 68 citations in our database are historical—there is no active enforcement trend for this code at this time. However, the 100.0% OOS rate on the 68 citations that were issued indicates strict enforcement whenever the violation occurs.
You can submit a DataQs (Roadside Data Quality Dispute) challenge through FMCSA if you believe the citation is inaccurate or improperly documented. DataQs works best for factual disputes—e.g., the inspector misidentified the vehicle, the defect was already corrected, or the inspection procedure was improper. If the defect genuinely exists, a DataQs challenge is unlikely to succeed. Consult your carrier's compliance team before submitting.
Across our 68 all-time citations, Freightliner trucks account for the largest share at 15 citations, followed by Ford with 10 citations and Peterbilt and Dodge tied at 7 citations each. Mack, Kenworth, and several others also appear in the violation record. This suggests the violation is vehicle-type agnostic and is tied to maintenance practices rather than manufacturer defect.
J & J Hernandez Inc (USDOT 1929976) and Northwind Transport LLC (USDOT 2090653) each have 2 citations for 393.52(a) in our database. Eight other carriers have one citation each. The low citation volume across the board suggests 393.52(a) violations are not concentrated in any single carrier's fleet—they are isolated incidents across diverse operations.
The 100.0% OOS rate reflects the severity and non-negotiable nature of what 393.52(a) addresses. Unlike minor defects that can sometimes be corrected in-transit or pose lower safety risk, violations triggering this code are critical enough that regulators will not permit continued operation. The contrast with peer codes—393.9(a) at 15.4%, 396.3(a)(1) at 45.3%, and 393.11 at 1.8%—shows that 393.52(a) sits at the top tier of enforcement urgency.
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.
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