Violation code

393.42A

No Brakes On All Wheels As Required

Not in SMSOOS· FMCSA A&I All Violations

393.42A is a Vehicle violation under 49 CFR §393.42A. It is an out-of-service violation; it is not scored in the SMS. Nationally it was cited 176 times in the last five years, with an OOS rate of 15.3%.

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National roadside inspection stats

as of 6/20/2026

Inspections

106

that found this code

Violations

176

total written

OOS rate

15.3%

27 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.

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Not used in SMS BASIC scoring

Recorded on your inspection report and visible on the PSP, but contributes 0 points to CSA BASIC scores — even if cited Out-of-Service.

Violation group: Vehicle
Regulation §: 393.42A
Severity weight: N/A
Used in SMS: No
Status: Active
Updated: 6/20/2026

Last updated June 2026

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Challenging 393.42A through FMCSA DataQs

If this violation was written incorrectly, here are the angles trucking-safety managers use to contest it. Playbook: Codes not used in SMS scoring.

Common ways to challenge this code

Not used in SMS — should not affect BASIC
This code is on the inspection report but is excluded from SMS BASIC scoring per Appendix A. Use DataQs to correct the underlying data quality issue if the code was written in error, but understand it does not affect the CSA percentile.
Evidence that wins
- ✓FMCSA SMS Methodology Appendix A reference
- ✓Underlying inspection report

Common pitfalls — avoid these

⚠These codes still appear on PSP — challenge the data if the cite was wrong

⚡ Draft a challenge for 393.42A →Read the DataQs guide first

Other Vehicle codes

Codes under the same FMCSA violation group

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Frequently asked questions about 393.42A

What does violation 393.42A mean?

393.42A is the FMCSA roadside-inspection violation code for "No Brakes On All Wheels As Required", part of the Vehicle group, cited under 49 CFR §393.42A.

What BASIC does 393.42A affect?

393.42A is not scored in any CSA BASIC. It is recorded on the inspection report and appears on the PSP, but it contributes 0 points to a carrier's SMS BASIC percentiles.

Is 393.42A an out-of-service (OOS) violation?

Yes. 393.42A is an out-of-service violation, meaning the driver or vehicle can be placed out of service at the roadside until the issue is corrected. OOS violations also add an extra severity point in SMS scoring.

How many CSA points does 393.42A add?

393.42A adds 0 CSA points because it is not used in SMS scoring, even when written out of service.

Can 393.42A be challenged through DataQs?

Yes. If you believe 393.42A 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.

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