FMCSR 393.75A2: Tire Tread/Sidewall Separation — Driver Q&A

It can, but it doesn't always. Across all-time inspection records, 393.75A2 carries a 13.5% OOS rate — meaning 1,529 out of 11,338 citations resulted in the vehicle being placed out of service. That's notably lower than the all-FMCSR average OOS rate of 31.4%, so most drivers cited under this code keep rolling. However, the risk isn't zero, and state enforcement patterns vary dramatically: in New Mexico, inspectors placed vehicles OOS on 71.1% of 393.75A2 citations in the last 180 days, compared to just 10.2% in Texas. Know where you're running.

The severity weight for 393.75A2 is not published in the available data, so a specific point value cannot be confirmed here. What the inspection records do show is that this code is cited frequently — ranked #210 out of 3,036 FMCSR codes by all-time citation volume with 11,338 total citations — placing it well inside the top 10% of all codes by enforcement activity. Any citation that appears on your inspection record feeds into the FMCSA's Vehicle Maintenance BASIC score. A violation cited within the last 6 months carries the heaviest time weight in the CSA scoring model, so recent citations matter most.

Get the tire inspected and documented immediately, and look at the rest of the vehicle. Our inspection records show that 393.75A2 rarely travels alone. In the last 90 days, inspections that included this violation also flagged inoperable required lamps (393.9) in 467 shared inspections, brake tubing/hose issues (393.45B2UV) in 409, and fuel system leaks (396.5B) in 292. Steps to take right now:

1. Have the cited tire replaced or repaired before your next dispatch.
2. Walk the entire rig — check all lights, brake lines, and fuel connections.
3. Get a signed repair order with date and technician name.
4. Keep that paperwork; you'll need it for any DataQs challenge or safety audit.

Moderately serious by OOS rate, very active by citation volume. The 13.5% OOS rate for 393.75A2 sits well below the all-FMCSR average of 31.4%, which puts it toward the lower-risk end of enforcement outcomes. For context, peer Vehicle Maintenance code 396.3(a)(1) carries a 45.3% OOS rate across 236,919 citations. That said, 393.75A2 has generated 7,439 citations in just the last 12 months, and enforcement activity has been climbing — October 2025 alone saw 784 citations. High volume means inspectors are actively looking for this defect, so low OOS rate doesn't mean low scrutiny.

Yes, you can submit a DataQs Request for Data Review (RDR), but success depends on what you're disputing. Because 393.75A2 is an equipment finding — a physical condition of the tire — a successful challenge typically requires evidence that the defect didn't exist at the time of inspection (repair records dated before the inspection, photos, or a second inspection report). Documentation errors on the inspection report, such as a wrong vehicle unit number or incorrect regulation code, are generally easier to correct. The inspection record stays on your PrePass/SMS profile for 24 months, so contesting early matters. File at the FMCSA DataQs portal and attach all supporting repair documentation.

Texas is by far the heaviest enforcement state for this violation. In the last 180 days, Texas issued 3,485 citations for 393.75A2 — dwarfing every other state in our inspection database. New Mexico ranked second with 38 citations, followed by Illinois with 28. If your routes run through Texas, especially along border corridors, this violation deserves extra pre-trip attention. The top carriers cited all-time are predominantly Mexico-based carriers operating in that Texas–New Mexico corridor, which aligns with the geographic concentration of enforcement activity.

Don't wait. Tread or sidewall separation is a progressive failure mode — it gets worse under load and heat. Our inspection records show 1,658 citations for 393.75A2 in just the last 90 days, and the monthly trend has been rising: citations went from 580 in May 2025 to 784 in October 2025. Enforcement momentum is up, meaning more inspectors are flagging this defect. Even though the overall OOS rate is 13.5%, certain states like North Carolina (70.0% OOS rate on 20 citations) and New Mexico (71.1% OOS rate on 38 citations) are pulling trucks for it at very high rates. A failed tire on the road is also a crash risk that no schedule justifies.

Both, but in different ways. FMCSA's CSA system attributes equipment violations like 393.75A2 primarily to the carrier's Vehicle Maintenance BASIC, since the carrier is responsible for ensuring the vehicle is roadworthy before dispatch. However, if a driver conducted a pre-trip inspection and signed off on a vehicle with visible tread or sidewall separation, that driver's inspection record can also reflect the finding. Our database shows 11,338 all-time citations for this code, with the heaviest citation concentrations at specific carriers — SERVICIO DE TRANSPORTE INTERNACIONAL Y LOCAL SA DE CV (USDOT 557341) leads with 167 citations all-time, indicating that repeat equipment failures accumulate against carrier safety scores over time.