393.9B-LSLO — Lighting - Stop lamps - Any obscured.
FMCSA violation code under Vehicle Maintenance. 775 events recorded in roadside inspections. Severity weight: 6.
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. It carries a severity weight of 6, 775 citations have been recorded against this code in the FMCSA inspection record.
- Code:
- 393.9B-LSLO
- Code System:
- FMCSR
- BASIC Category:
- Vehicle Maintenance
- OOS Eligible:
- No
- Severity Weight:
- 6
- Violation Group:
- Lighting
- Total Events:
- 775
- Carriers Cited:
- 611
Ranks #826 of 3,146 FMCSR codes by citation frequency • OOS rate of 2.3% is below the FMCSR-wide average of 33.3%.
What 393.9B-LSLO means
Lighting - Stop lamps - Any obscured.
This is a specific FMCSA dictionary variant of section 393.9; it is not interchangeable with the bare 393.9 catch-all code.
CSA/SMS severity weight 6 on FMCSA's 1–10 scale in the Vehicle Maintenance BASIC.
Not Out-of-Service eligible by itself; the citation still feeds the carrier's BASIC percentile when scored.
775 citations recorded in the FMCSA inspection mirror across 611 carriers.
Ranks #826 of 3,146 FMCSR codes by citation frequency.
Most cited recently in Texas (37 events in the last 180 days).
How to use this code
CSA weight, OOS trigger, inspector focus, fix path, and DataQs — from published FMCSA fields and citation counts on this page
CSA / SMS weight
Severity weight 6 (1–10). Higher weights correlate more strongly with crash risk in FMCSA's published table. Rolls into the Vehicle Maintenance BASIC. SMS applies time weights (3× / 2× / 1×) over a 24-month window before ranking carriers by percentile.
OOS trigger
This code is not OOS-eligible by itself. It still appears on the inspection report and can move the carrier's BASIC percentile. Note: 18 co-occurring OOS flags appear on inspections that also cited 393.9B-LSLO — those OOS orders came from other defects on the same stop.
What inspectors typically check
FMCSR violations for brake defects, tire issues, lighting failures, frame damage, and other mechanical deficiencies.
- Brake condition, adjustment, and air-system integrity
- Tire tread/condition, lighting, and reflectors
- Frame, coupling, cargo securement, and other mechanical defects
Fix and prevent
- Correct the underlying condition and document the fix (date, work performed, who signed off).
- Catch it on pre-trip and scheduled PM before a roadside Level I/II does — brakes, tires, and lamps dominate this BASIC.
- Keep the correction in the compliance file — undocumented fixes look the same as non-compliance in a review.
DataQs challenge grounds
Carriers and drivers can file a Request for Data Review within 24 months when the record itself looks wrong. Common accepted grounds:
- Wrong violation code for the condition the inspector described
- Citation attributed to the wrong USDOT, driver, or unit
- Condition was already corrected / not present when the report was finalized
- Supporting evidence (photos, receipts, calibration, ELD extract) contradicts the citation
For brokers and shippers
Severity 6/10 — weigh frequency and recency on the carrier's inspection history, not a single old citation. Most-cited carrier in our table: AUTO HAUL EXPRESS LLC (4 citations). 611 carriers have at least one 393.9B-LSLO citation in the mirror — open a carrier's inspection list to see whether this code is a pattern or a one-off.
Violation Description
Lighting - Stop lamps - Any obscured.
Regulatory Reference
Federal Motor Carrier Safety Regulations
This violation references 49 CFR 393.9B in the Federal Motor Carrier Safety Regulations.
Top Enforcing States
Where 393.9B-LSLO is most commonly cited (last 180 days)
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.
Most Active Stations
Inspection stations citing 393.9B-LSLO most often (last 180 days)
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 | WASTE MANAGEMENT OF PENNSYLVANIA INC | 344050 | 3 |
| #3 | HUGILL SANITATION INC | 2114510 | 3 |
| #4 | CREACH GREENHOUSE INC | 717941 | 2 |
| #5 | ASV XPRESS LLC | 4389301 | 2 |
| #6 | CARRIER ONE INC | 1102122 | 2 |
| #7 | J B HUNT TRANSPORT INC | 80806 | 2 |
| #8 | FIRST CLASS AUTO SALVAGE INC | 2069438 | 2 |
| #9 | NEW PRIME INC | 3706 | 2 |
| #10 | LADA TRANS INC | 2998381 | 2 |
| #11 | KEVIN J TORREY | 3136657 | 2 |
| #12 | SAKARA LLC | 4429530 | 2 |
| #13 | TIGER LINES LLC | 80289 | 2 |
| #14 | BM 5 EXPRESS LLC | 4252114 | 2 |
| #15 | BUMBLE TRUCK LLC | 4475014 | 2 |
| #16 | CORTEN INDUSTRIES INC | 3153092 | 2 |
| #17 | RIVERCITY LOGISTICS LTD | 3652295 | 2 |
| #18 | FEDERAL EXPRESS CORPORATION | 86876 | 2 |
| #19 | CRST EXPEDITED INC | 53773 | 2 |
| #20 | GTR EXPRESS LLC | 4252559 | 2 |
| #21 | WTI TRANSPORT LLC | 389263 | 2 |
| #22 | EVERGRO COOPERATIVE | 2450546 | 2 |
| #23 | AKA FS LLC | 3899976 | 2 |
| #24 | ANDY TRANSPORT INC | 1547667 | 1 |
| #25 | GILBERTO CARRANZA GOMEZ | 786840 | 1 |
Recent Inspections
Latest inspections where 393.9B-LSLO was cited • 775 total events • Page 1 of 31
| Date | Report # | State | Level | OOS |
|---|---|---|---|---|
| 88955467 | MD | Level 2 | No | |
| 88952319 | FL | Level 2 | No | |
| 88946889 | TX | Level 2 | No | |
| 88946319 | TX | Level 2 | No | |
| 88918002 | AZ | Level 2 | No | |
| 88908662 | MI | Level 2 | No | |
| 88904671 | MA | Level 2 | No | |
| 88895932 | WY | Level 1 | No | |
| 88894990 | KY | Level 2 | No | |
| 88881942 | CA | Level 2 | No | |
| 88869447 | KY | Level 2 | Yes | |
| 88867739 | NC | Level 2 | No | |
| 88833108 | FL | Level 2 | No | |
| 88810489 | NC | Level 2 | No | |
| 88819821 | TX | Level 2 | No | |
| 88790416 | NE | Level 1 | No | |
| 88788315 | MD | Level 1 | No | |
| 88770856 | CO | Level 2 | No | |
| 88750373 | CA | Level 2 | No | |
| 88735833 | PA | Level 1 | No | |
| 88737535 | TX | Level 2 | No | |
| 88736534 | TX | Level 2 | No | |
| 88732083 | FL | Level 2 | No | |
| 88708814 | NC | Level 1 | Yes | |
| 88708733 | MI | Level 2 | No |
How to comply with violation code 393.9B-LSLO
- 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.
- 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.
- 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.
- 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.
- 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? ▾
Is 393.9B-LSLO an out-of-service violation? ▾
What's the severity weight of 393.9B-LSLO? ▾
How many inspections have cited 393.9B-LSLO? ▾
Which BASIC category is 393.9B-LSLO in? ▾
What does a carrier do to fix 393.9B-LSLO? ▾
Where can I find related violation codes? ▾
Where can I find the full text of 393.9B-LSLO? ▾
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.