Violation code

393.75(a)

Flat tire or fabric exposed

Vehicle Maintenance8Non-OOS· SMS Appendix A v3.20

393.75(a) is a Tires violation under 49 CFR §393.75(a). It falls in the Vehicle Maintenance BASIC with a severity weight of 8/10. Nationally it was cited 83,574 times in the last five years, with an OOS rate of 93.5%.

📊

National roadside inspection stats

as of 8/20/2026

Inspections

75,018

that found this code

Violations

83,574

total written

OOS rate

93.5%

78,151 OOS

Source: FMCSA roadside inspection data (last 5 years). The OOS rate is the share of these violations that led the officer to mark the driver or vehicle out of service.

Violation group: Tires
Regulation §: 393.75(a)
Severity weight: 8
Used in SMS: Yes
Status: Active
Updated: 8/20/2026

Last updated August 2026

⚡

Think this violation was written incorrectly?

Generate a polished DataQs challenge letter for 393.75(a) in about 5 seconds. AI quotes the CFR, predicts your grant chance.

⚡ Draft a challenge →

Notes

DSMS: Y

What 393.75(a) means — and how to avoid it

In plain English

In plain terms, 393.75(a) is cited for flat tire or fabric exposed. It falls under the FMCSA rules on parts and accessories needed for safe operation.

What the inspector checks

•Tread depth (4/32" steer, 2/32" others) and even wear
•Cuts, bulges, sidewall damage, or exposed cord/ply
•Proper inflation and matched duals
•Flat/audible-leak tires — an automatic out-of-service item

How to prevent it

✓Thump or gauge every tire on the pre-trip, including inside duals
✓Replace before tread hits the limit, not after
✓Keep a working gauge in the truck and correct low pressure immediately

How it affects your CSA

up to 24 pts (fresh)

Severity 8/10. A fresh citation counts at the 3× time weight — up to 24 points toward the Vehicle Maintenance BASIC — then tapers to 2× after 6 months and 1× after a year, dropping off the score at 24 months.

General guidance from the violation’s FMCSA classification — not legal advice, and not a substitute for the inspector’s findings or 49 CFR.

📚

Challenging 393.75(a) through FMCSA DataQs

If this violation was written incorrectly, here are the angles trucking-safety managers use to contest it. Playbook: Tires.

Relevant 49 CFR49 CFR § 393.75

Tires

“No motor vehicle shall be operated on any tire that has body ply or belt material exposed through the tread or sidewall, has any tread or sidewall separation, is flat or has an audible leak, or has a cut to the extent that the ply or belt material is exposed.”

Common ways to challenge this code

Tread measurement disputed
The tread depth measurement was taken at a worn point that is not representative, contrary to NHTSA/FMCSA measurement standards.
Evidence that wins
- ✓Independent tread gauge reading from same tire (multiple positions)
- ✓Photograph of the tire with a reference scale
Inflation context — recent stop or temperature
The under-inflation reading was taken immediately after a long-distance high-temperature run or before warm-up, not at the FMCSA standard measurement state.
Evidence that wins
- ✓Tire-pressure-monitoring system log (TPMS)
- ✓Service receipt showing inflation at start of trip

Common pitfalls — avoid these

⚠Inflation readings can't be challenged with a re-inflation done after the stop — must show original-state evidence

⚡ Draft a challenge for 393.75(a) →Read the DataQs guide first

More codes in Vehicle Maintenance

Same BASIC category — ranked by national citation volume

View all Vehicle Maintenance codes →

Other Tires codes

Codes under the same FMCSA violation group

❓

Frequently asked questions about 393.75(a)

What does violation 393.75(a) mean?

393.75(a) is the FMCSA roadside-inspection violation code for "Flat tire or fabric exposed", part of the Tires group, cited under 49 CFR §393.75(a).

What BASIC does 393.75(a) affect?

393.75(a) falls under the Vehicle Maintenance BASIC in the FMCSA Safety Measurement System (SMS).

What is the CSA severity weight of 393.75(a)?

393.75(a) carries a severity weight of 8 out of 10. Higher weights indicate violations more closely tied to crash risk, and they count more toward a carrier's Vehicle Maintenance score.

Is 393.75(a) an out-of-service (OOS) violation?

No. 393.75(a) is not an out-of-service violation, so on its own it does not trigger an out-of-service order at the roadside.

How many CSA points does 393.75(a) add to a carrier's score?

The point contribution of 393.75(a) depends on its severity weight (8/10) multiplied by a time weight of 3, 2, or 1 based on how recent the inspection is. You can calculate the exact contribution with the CSA points calculator.

How can a driver prevent 393.75(a)?

Thump or gauge every tire on the pre-trip, including inside duals; Replace before tread hits the limit, not after; Keep a working gauge in the truck and correct low pressure immediately.

Can 393.75(a) be challenged through DataQs?

Yes. If you believe 393.75(a) was recorded in error, you can file a Request for Data Review (RDR) through the FMCSA DataQs system with supporting evidence. A successful challenge can remove or correct the violation on your record.

Keep going

CSA points calculator How to challenge a violation Draft a DataQs letter for 393.75(a)Vehicle Maintenance BASIC Carrier CSA lookup CSA glossary

Turn this violation into a training moment

Assign training on this exact topic — and prove it

Looking up a code is step one. FleetTrained — built by the same safety manager behind VioCodes — lets you assign a video on this topic; drivers quiz and sign in their language, and you get a DOT-ready certificate so it stops happening.