393.9B-LSLO — Lighting - Stop lamps - Any obscured

FMCSA violation code under Vehicle Maintenance. 690 events recorded in roadside inspections. Severity weight: N/A.

Violation code 393.9B-LSLO is a Federal Motor Carrier Safety Regulations citation issued under 49 CFR 393.9. It tracks a specific compliance failure recorded against motor carriers and drivers during FMCSA roadside inspections. The code rolls up into the FMCSA Safety Measurement System (SMS) Vehicle Maintenance BASIC, which feeds the carrier's percentile ranking and prioritization for FMCSA interventions. It applies to interstate motor carriers, drivers, and the commercial motor vehicles they operate; intrastate operators are subject when their state has adopted Part 350 of the FMCSR by reference. 690 citations have been recorded against this code in the FMCSA inspection record.

Severity Weight
N/A
OOS Eligible
No
BASIC Category
Vehicle Maintenance
Total Events
690
Code:
393.9B-LSLO
Code System:
FMCSR
BASIC Category:
Vehicle Maintenance
OOS Eligible:
No
Severity Weight:
N/A
Total Events:
690
Carriers Cited:
611

Ranks #843 of 3,146 FMCSR codes by citation frequency • OOS rate of 2.3% is below the FMCSR-wide average of 33.2%.

Violation Description

Lighting - Stop lamps - Any obscured

About This Violation Code

Code 393.9B-LSLO falls under the Vehicle Maintenance BASIC category in FMCSA's Safety Measurement System (SMS).

When this violation is cited during a roadside inspection, it contributes to the carrier's Vehicle Maintenance BASIC score. Carriers with high BASIC percentiles may be prioritized for FMCSA interventions including warning letters, investigations, or compliance reviews.

Regulatory Reference

Federal Motor Carrier Safety Regulations

This violation references 49 CFR 393.9B in the Federal Motor Carrier Safety Regulations.

Events (all time)
690
OOS Events
16
OOS Rate
2.3%
Top State (180d)
Pennsylvania
17 events

Top Enforcing States

Where 393.9B-LSLO is most commonly cited (last 180 days)

1. Pennsylvania
17
OOS 5.9%
2. California
12
OOS 0.0%
3. Arizona
10
OOS 0.0%
4. Florida
8
OOS 0.0%
5. South Carolina
7
OOS 0.0%
6. Kansas
7
OOS 0.0%
7. Missouri
6
OOS 0.0%
8. US
5
OOS 0.0%
9. Connecticut
5
OOS 0.0%
10. New York
5
OOS 0.0%
11. Colorado
5
OOS 0.0%
12. Ohio
5
OOS 0.0%
13. Virginia
5
OOS 0.0%
14. Maryland
4
OOS 0.0%
15. Georgia
4
OOS 0.0%

Click a state to see roadside inspection activity, top stations, and carrier profiles in that jurisdiction.

Citation Trend (12 months)

Monthly count of 393.9B-LSLO citations. Red bars mark months with OOS-triggering citations.

18
2025-07
46
2025-08
42
2025-09
29
2025-10
34
2025-11
30
2025-12
46
2026-01
36
2026-02
32
2026-03
2
2026-04
15
2026-05
26
2026-06
9
2026-07

Most Active Stations

Inspection stations citing 393.9B-LSLO most often (last 180 days)

1. PA
4
OOS 0.0%
2. GREEN COVE SPRINGS FL
2
OOS 0.0%
3. DUNDALK MD
2
OOS 0.0%
4. JACKSON OH
2
OOS 0.0%
5. MEMPHIS TN
2
OOS 0.0%
6. NEWTON KS
2
OOS 0.0%
7. YUMA AZ
1
OOS 0.0%
8. PHOENIX AZ
1
OOS 0.0%
9. BUCKEYE AZ
1
OOS 0.0%
10. I-15 NB S OF SR-138
1
OOS 0.0%

Often Cited Together

Other violations commonly found on the same inspection (last 90 days)

Citation patterns suggest related root causes (e.g., HOS violations paired with logbook errors).

Top Carriers Cited

Ranked by frequency • 611 carriers total • Page 1 of 25

# Carrier USDOT # Violations
#1 AUTO HAUL EXPRESS LLC 4329325 4
#2 HUGILL SANITATION INC 2114510 3
#3 WASTE MANAGEMENT OF PENNSYLVANIA INC 344050 3
#4 RIVERCITY LOGISTICS LTD 3652295 2
#5 TIGER LINES LLC 80289 2
#6 CARRIER ONE INC 1102122 2
#7 AKA FS LLC 3899976 2
#8 CRST EXPEDITED INC 53773 2
#9 EVERGRO COOPERATIVE 2450546 2
#10 GTR EXPRESS LLC 4252559 2
#11 SAKARA LLC 4429530 2
#12 ASV XPRESS LLC 4389301 2
#13 BM 5 EXPRESS LLC 4252114 2
#14 CORTEN INDUSTRIES INC 3153092 2
#15 BUMBLE TRUCK LLC 4475014 2
#16 FEDERAL EXPRESS CORPORATION 86876 2
#17 FIRST CLASS AUTO SALVAGE INC 2069438 2
#18 CREACH GREENHOUSE INC 717941 2
#19 NEW PRIME INC 3706 2
#20 WTI TRANSPORT LLC 389263 2
#21 LADA TRANS INC 2998381 2
#22 J B HUNT TRANSPORT INC 80806 2
#23 KEVIN J TORREY 3136657 2
#24 ANDY TRANSPORT INC 1547667 1
#25 ABC AUTOLINEAS SA DE CV 3090129 1

Recent Inspections

Latest inspections where 393.9B-LSLO was cited • 690 total events • Page 1 of 28

Date Report # State Level OOS
88347280 PA Level 2 No
88342965 WV Level 2 No
88333845 MO Level 2 No
88331907 KY Level 1 No
88317280 IA Level 1 No
88315898 AL Level 2 No
88305642 SC Level 2 No
88304874 IA Level 2 No
88299934 NC Level 1 No
88308063 MS Level 2 No
88269144 NY Level 1 No
88241037 NJ Level 2 No
88232859 AK Level 1 No
88240505 CA Level 1 No
88228619 SC Level 2 No
88216801 NC Level 1 No
88196367 FL Level 2 No
88179636 NJ Level 1 No
88180416 PA Level 1 No
88172333 CA Level 1 No
88164197 US Level 1 No
88158467 NC Level 2 No
88140115 AZ Level 1 No
88129429 AK Level 1 No
88112812 WV Level 2 No

How to comply with violation code 393.9B-LSLO

  1. Locate the regulation in the eCFR. Open https://www.ecfr.gov/current/title-49/section-393.9 on eCFR.gov to read the legal text the citation is written against. The eCFR is the National Archives' continuously updated electronic Code of Federal Regulations and is the canonical reference for any FMCSR section.
  2. Determine if your operation is subject. Confirm whether your operation is interstate (always subject to the FMCSR) or intrastate (subject when your state has adopted 49 CFR Part 350 by reference; most have). Intrastate operators in non-adopting states may be subject to a state analog instead of the federal rule.
  3. Identify the documented requirement. Read the requirement carefully: "Lighting - Stop lamps - Any obscured" Map it to the specific equipment, driver document, or operational practice it covers.
  4. Inspect or maintain to standard. Build a recurring inspection, training, or filing routine that catches this gap before a roadside inspector does. Pre-trip checks, scheduled preventive maintenance, driver-qualification file audits, and supervisor reviews are the standard places this kind of issue is caught early.
  5. Document compliance to demonstrate it on review. Keep a dated, signed record of each inspection, repair, training session, or filing tied to 393.9B-LSLO. During an FMCSA compliance review or a customer onboarding audit, the documentation is what proves the program runs — undocumented compliance is indistinguishable from non-compliance to the auditor.

Frequently asked questions about 393.9B-LSLO

What is FMCSA violation code 393.9B-LSLO?
Lighting - Stop lamps - Any obscured The citation appears as code 393.9B-LSLO on roadside inspection reports issued by the Federal Motor Carrier Safety Administration and rolls up into the Vehicle Maintenance BASIC.
Is 393.9B-LSLO an out-of-service violation?
No. Code 393.9B-LSLO is not Out-of-Service eligible. A citation under this code is recorded on the inspection report and counts toward the carrier's BASIC percentile, but it does not by itself trigger an Out-of-Service order at the roadside.
What's the severity weight of 393.9B-LSLO?
FMCSA hasn't published a severity weight for 393.9B-LSLO in the snapshot we mirror. Severity weights run from 1 to 10 on FMCSA's published violation table; codes without a weight are typically administrative or duplicative of weighted codes that already feed the BASIC percentile.
How many inspections have cited 393.9B-LSLO?
690 inspections in our FMCSA mirror cite 393.9B-LSLO, of which 16 (2.3%) resulted in Out-of-Service orders. The Recent Inspections table on this page lists the most recent citations with date, state, level, and OOS flag — click any row to see the full inspection report.
Which BASIC category is 393.9B-LSLO in?
393.9B-LSLO rolls up into the Vehicle Maintenance BASIC of FMCSA's Safety Measurement System. The BASIC determines how the citation feeds the carrier's percentile ranking — carriers with high percentiles in a BASIC are prioritized for FMCSA interventions including warning letters, focused investigations, and full compliance reviews.
What does a carrier do to fix 393.9B-LSLO?
Resolving a 393.9B-LSLO citation has two parts: (1) correct the underlying condition immediately — repair the equipment defect, retrain the driver, file the missing form, or update the maintenance record — and (2) document the correction in the carrier's compliance file, ideally with date, time, and the name of the person who performed the work. Carriers that believe the citation was recorded in error can file a Request for Data Review through the FMCSA DataQs system within 24 months of the inspection date.
Where can I find related violation codes?
The "Often Cited Together" panel on this page lists violations frequently appearing on the same inspection as 393.9B-LSLO — these usually share a root cause (for example, an HOS violation paired with a logbook error). The All Violation Codes index links to every code in the system, and the BASIC category page lists every code in Vehicle Maintenance.
Where can I find the full text of 393.9B-LSLO?
The full regulatory text is published on eCFR.gov at 49 CFR 393.9. The eCFR is the official, continuously updated electronic Code of Federal Regulations maintained by the National Archives. The TruckCodex page mirrors enforcement data; the eCFR has the legal text the citation is written against.

About FMCSA violation codes

Every violation found during an FMCSA roadside inspection is recorded under a code drawn from the Federal Motor Carrier Safety Regulations — the codified safety rules motor carriers, drivers, and commercial motor vehicles must comply with in interstate commerce. Codes roll up into one of seven Behavior Analysis and Safety Improvement Categories (BASICs): Unsafe Driving, Hours-of-Service, Driver Fitness, Controlled Substances/Alcohol, Vehicle Maintenance, Hazardous Materials Compliance, and Crash Indicator. Each code carries a published severity weight (1–10) and an Out-of-Service eligibility flag.

Citations counted in the FMCSA Safety Measurement System (SMS) feed a 24-month rolling percentile rank for every motor carrier. Recent citations weigh more heavily than older ones — FMCSA applies a 3× multiplier to events 0–6 months old, 2× for 6–12 months, and 1× for 12–24 months. Carriers above the published intervention threshold for a given BASIC are prioritized for warning letters, focused investigations, and full compliance reviews.

TruckCodex mirrors the FMCSA Motor Carrier Management Information System (MCMIS) and the published violation dictionary on a daily refresh cycle. We do not author or modify violation records — every count, severity weight, and OOS flag on this page reflects what the FMCSA has on file. For real-time confirmation immediately before an enforcement decision, click through to the FMCSA Violations Search link above. Carriers who believe a citation was recorded in error can file a Request for Data Review through the FMCSA DataQs system.

Data sources & freshness

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.

Refreshed daily.

Vehicle recall campaigns, defect investigations, and consumer safety complaints (SCRS).

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EIA

Retail diesel and gasoline price history and state fuel-tax tables.

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Cross-border carrier registry and Canadian recall campaigns where applicable.

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TruckCodex is an independent aggregator; it is not affiliated with FMCSA, NHTSA, EIA, or Transport Canada. Always verify compliance-critical information directly with the originating agency.