Violation code

393.86

No or improper rearend protection

Not in SMSNon-OOS· FMCSA A&I All Violations

393.86 is a Vehicle violation under 49 CFR §393.86. It is not scored in the SMS. Nationally it was cited 26 times in the last five years, with an OOS rate of 0.0%.

📊

National roadside inspection stats

as of 9/20/2026

Inspections

that found this code

Violations

total written

OOS rate

0.0%

0 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.

📎

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 §: 393.86
Severity weight: N/A
Used in SMS: No
Status: Active
Updated: 9/20/2026

Last updated September 2026

⚡

Think this violation was written incorrectly?

Generate a polished DataQs challenge letter for 393.86 in about 5 seconds. AI quotes the CFR, predicts your grant chance.

⚡ Draft a challenge →

What 393.86 means — and how to avoid it

In plain English

In plain terms, 393.86 is cited for no or improper rearend protection. It falls under the FMCSA rules on parts and accessories needed for safe operation.

What the inspector checks

•The specific component cited is present, secure, and functional
•No damage, leaks, or wear beyond limits

How to prevent it

✓Catch it on a thorough pre-trip walk-around
✓Fix equipment defects before dispatch and log the repair

How it affects your CSA

0 CSA points

393.86 is not scored in the SMS. It adds 0 CSA points — even if written out-of-service — but it still appears on the inspection report and the driver’s PSP.

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

📚

Challenging 393.86 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 393.86 →Read the DataQs guide first

Other Vehicle codes

Codes under the same FMCSA violation group

❓

Frequently asked questions about 393.86

What does violation 393.86 mean?

393.86 is the FMCSA roadside-inspection violation code for "No or improper rearend protection", part of the Vehicle group, cited under 49 CFR §393.86.

What BASIC does 393.86 affect?

393.86 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 393.86 an out-of-service (OOS) violation?

No. 393.86 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 393.86 add?

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

How can a driver prevent 393.86?

Catch it on a thorough pre-trip walk-around; Fix equipment defects before dispatch and log the repair.

Can 393.86 be challenged through DataQs?

Yes. If you believe 393.86 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 393.86 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.