393.9B-LFTSO — Lighting - Front - Turn signal - obscured.

FMCSA violation code under Vehicle Maintenance. 439 events recorded in roadside inspections. Severity weight: 6.

Violation code 393.9B-LFTSO 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, 439 citations have been recorded against this code in the FMCSA inspection record.

Severity Weight
6
OOS Eligible
No
BASIC Category
Vehicle Maintenance
Total Events
439
Code:
393.9B-LFTSO
Code System:
FMCSR
BASIC Category:
Vehicle Maintenance
OOS Eligible:
No
Severity Weight:
6
Violation Group:
Lighting
Total Events:
439
Carriers Cited:
368

Ranks #989 of 3,146 FMCSR codes by citation frequency • OOS rate of 0.5% is below the FMCSR-wide average of 33.4%.

What 393.9B-LFTSO means

Lighting - Front - Turn signal - 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.

439 citations recorded in the FMCSA inspection mirror across 368 carriers.

Ranks #989 of 3,146 FMCSR codes by citation frequency.

Most cited recently in California (20 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.

All Vehicle Maintenance codes →

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: 2 co-occurring OOS flags appear on inspections that also cited 393.9B-LFTSO — 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

Vehicle Maintenance category →

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: JESUS MA VALDEZ GARCIA (3 citations). 368 carriers have at least one 393.9B-LFTSO 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 - Front - Turn signal - obscured.

Regulatory Reference

Federal Motor Carrier Safety Regulations

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

Events (all time)
439
OOS Events
2
OOS Rate
0.5%
Top State (180d)
California
20 events

Top Enforcing States

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

1. California
20
OOS 0.0%
2. Arizona
16
OOS 0.0%
3. Pennsylvania
7
OOS 0.0%
4. Maryland
5
OOS 0.0%
5. New Jersey
4
OOS 0.0%
6. US
3
OOS 0.0%
7. Iowa
3
OOS 0.0%
8. Michigan
3
OOS 0.0%
9. Colorado
2
OOS 0.0%
10. Montana
2
OOS 0.0%
11. Florida
2
OOS 0.0%
12. Missouri
1
OOS 0.0%
13. Mississippi
1
OOS 100.0%
14. Connecticut
1
OOS 0.0%
15. Georgia
1
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-LFTSO citations. Red bars mark months with OOS-triggering citations.

5
2025-07
32
2025-08
20
2025-09
19
2025-10
14
2025-11
20
2025-12
13
2026-01
9
2026-02
17
2026-03
1
2026-04
15
2026-05
12
2026-06
20
2026-07

Most Active Stations

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

2. CORDELIA IF
2
OOS 0.0%
5. I-15 NB SO POMERADO
1
OOS 0.0%
6. SAN ONOFRE IF
1
OOS 0.0%
7. HANFORD AREA
1
OOS 0.0%
8. BAKERSFIELD AREA
1
OOS 0.0%
9. MONUMENT CO
1
OOS 0.0%
10. WEST MEMPHIS AR
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 • 368 carriers total • Page 1 of 15

# Carrier USDOT # Violations
#1 JESUS MA VALDEZ GARCIA 2534784 3
#2 RICHARD ALAN OWENS JR 2009044 3
#3 LT DELIVERY INC 574693 3
#4 JESUS DAVID BALDERRAMA FIGUEROA 2948994 2
#5 HUMMING BIRD TRANSPORTATION LLC 3469059 2
#6 DARLING INGREDIENTS INC 471318 2
#7 HOME BUILDERS SITE SERVICES OF ARIZONA 1971902 2
#8 TOWER TRUCK LINES INC 1331901 2
#9 RICARDO CARDENAS GARCIA 3356079 2
#10 CARLOS GUADALUPE GARCIA GARCIA 1916245 2
#11 MCCARTHY TOWING INC 1380659 2
#12 MMM-EXPRESS XPD LLC 2458809 2
#13 BS 147 INC 3723120 2
#14 BAXLEY'S ENTERPRISES INC 700252 2
#15 MSV CORPORATION 3693170 2
#16 NANO TRUCKING LLC 3656517 2
#17 BEST WORKER GROUP INC 3136354 2
#18 TYCSO SA DE CV 3888136 2
#19 GJD MASONRY AND PAVER 4086871 2
#20 PITT OHIO EXPRESS LLC 190180 2
#21 GILBERTO CARRANZA-GOMEZ 786840 2
#22 NEW DIXIE MARCO INC 1068132 1
#23 HARK TRANS INC 2640949 1
#24 UE LINE INC 2790763 1
#25 HAILEY'S HOT SHOT LLC 2422846 1

Recent Inspections

Latest inspections where 393.9B-LFTSO was cited • 439 total events • Page 1 of 18

Date Report # State Level OOS
88517126 CA Level 1 No
88507715 NJ Level 2 No
88500151 PA Level 2 No
88484242 NJ Level 2 No
88496795 AZ Level 2 No
88494314 TN Level 2 No
88493059 AZ Level 2 No
88482656 IA Level 2 No
88453771 AZ Level 2 No
88453438 AZ Level 2 No
88450336 MD Level 2 No
88452203 AZ Level 2 No
88431576 CA Level 1 No
88418506 CA Level 1 No
88413056 AZ Level 2 No
88387559 MD Level 2 No
88376231 CA Level 1 No
88305465 US Level 1 No
88292565 NJ Level 2 No
88292401 NJ Level 2 No
88288596 AZ Level 1 No
88263339 FL Level 2 No
88230604 MA Level 2 No
88196693 AZ Level 2 No
88195957 AZ Level 2 No

How to comply with violation code 393.9B-LFTSO

  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 - Front - Turn signal - 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-LFTSO. 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-LFTSO

What is FMCSA violation code 393.9B-LFTSO?
Lighting - Front - Turn signal - obscured. The citation appears as code 393.9B-LFTSO on roadside inspection reports issued by the Federal Motor Carrier Safety Administration and rolls up into the Vehicle Maintenance BASIC.
Is 393.9B-LFTSO an out-of-service violation?
No. Code 393.9B-LFTSO 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-LFTSO?
393.9B-LFTSO carries a severity weight of 6 on FMCSA's 1–10 scale. Higher weights indicate violations more strongly correlated with crash risk; FMCSA multiplies the weight by a time factor (3× for citations 0–6 months old, 2× for 6–12 months, 1× for 12–24 months) when computing the carrier's Safety Measurement System percentile.
How many inspections have cited 393.9B-LFTSO?
439 inspections in our FMCSA mirror cite 393.9B-LFTSO, of which 2 (0.5%) 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-LFTSO in?
393.9B-LFTSO 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-LFTSO?
Resolving a 393.9B-LFTSO 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-LFTSO — 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-LFTSO?
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.