What 393.9A-LIL means in plain language
This citation means an inspector found at least one lamp on your commercial motor vehicle that is required by federal safety rules but was not working at the time of the inspection. Required lamps cover a broad range of lighting — headlights, taillights, brake lights, turn signals, clearance lamps, and marker lights are all in scope. If any of those are dark when they should be lit, you are operating out of compliance.
The rule itself is straightforward: every lamp that federal regulations require your CMV to have must actually function. It is not enough for the hardware to be physically present — the bulb, wiring, and circuit all have to work. A burned-out bulb you did not know about is treated the same as one you ignored.
This specific sub-code, 393.9A-LIL, targets inoperable lamps broadly. You will notice that several closely related sub-codes exist for more specific lamp types — clearance lamps, side-marker lamps, reflective lamps, and others. A single inspection can produce citations across more than one of these sub-codes if multiple lamp systems are down.
What our enforcement data actually shows
Across our 13 million+ inspection records, 393.9A-LIL has accumulated 95,458 all-time citations, making it the 19th most-cited code out of 3,036 FMCSR codes in our database. That is not a fringe violation — it is deep inside the top 1% of all federal codes by enforcement volume.
The out-of-service rate for this code is 0.0%. Every one of the 95,458 citations resulted in a notation on the inspection report, but not a single driver was placed out of service. That stands in sharp contrast to the all-FMCSR average OOS rate of 31.4% across our inspection records. This code will not park your truck today, but it will follow you.
The enforcement pace is accelerating. Our inspection records show 58,547 citations in the last 12 months alone, and 12,123 citations in just the last 90 days. Monthly volume over the past year has been remarkably consistent — ranging from roughly 4,300 citations in slower months up to 5,670 in August 2025, with March 2026 climbing back to 5,619. This is not a seasonal anomaly; inspectors are writing this citation at a steady, high-volume pace year-round.
Who gets cited most
Looking at the last 180 days in our database, California leads all states with 2,161 citations, followed closely by New York with 2,009 citations and Florida with 1,897 citations. Maryland (1,719 citations) and the US unclassified/federal category (1,563 citations) round out the top five. All of these states show a 0.0% OOS rate, consistent with the national picture — inspectors everywhere are writing the citation but not pulling drivers off the road for it.
The OOS rate does not vary materially across any of the top ten states — every jurisdiction in our data is at 0.0% for this code. The meaningful difference between states is purely in enforcement intensity: California, New York, and Florida are collectively running inspection programs that generate far more of these citations than states like Washington (994 citations) or Georgia (982 citations) over the same period.
Our data shows fleets such as WESTERN EXPRESS INC (USDOT 511412) with 198 all-time citations and FEDERAL EXPRESS CORPORATION (USDOT 86876) with 195 all-time citations appearing at the top of the carrier list. Large fleets with thousands of power units in service will naturally accumulate more citations across all codes — what these numbers reflect is inspection exposure at scale.
How severe is this compared to similar codes
Within the Vehicle Maintenance category, the CSA severity weight for 393.9A-LIL is 3. That is on the lower end of the severity spectrum, but it adds to your CSA score and those points do not disappear quickly.
Compare this to the parent-level code 393.9(a) — Inoperable required lamps, which our inspection records show has 660,737 all-time citations and a 15.4% OOS rate. The parent code can park you; this sub-code currently does not — but they address the same underlying defect.
Look at 396.3(a)(1) — Inspection/repair/maintenance - general, which has 236,919 citations in our database and a 45.3% OOS rate. That is a code that will sideline your vehicle nearly half the time it is written. If your lamp defect is part of a broader maintenance failure, you could see both codes on the same inspection report.
Finally, 393.11 — Lighting devices/reflectors carries 179,734 citations in our records with a 1.8% OOS rate. It is in the same lighting family as 393.9A-LIL but triggers a slightly higher OOS exposure. Understanding where your citation sits in this cluster matters when you are building a case to dispute points or when your fleet safety manager is assessing CSA exposure.
How to avoid it
The co-occurring violation pattern in our data tells you exactly where your pre-trip needs to get sharper. In the last 90 days, 393.9A-LIL appeared on the same inspection report as other lamp sub-codes — 393.9A-LCL in 2,787 shared inspections, 393.9A-LSML in 1,721, and 393.9A-LLPL in 1,685. That means when one lamp is out, inspectors are finding multiple lamp failures on the same truck. One burned bulb is often a sign that you have not been walking the full perimeter.
- Complete a full lighting walk-around before every dispatch. Walk all four corners. Tap brake pedal, activate turn signals, and check hazards while a second person or a reflective surface confirms rear lamps. Do not stop after finding the first issue — our data shows multiple lamp failures on the same vehicle are extremely common.
- Check your proof of periodic inspection. 396.17C-PI (No proof of periodic inspection) appeared in 1,991 shared inspections with this code in the last 90 days. Carry your inspection documentation and make sure it is current.
- Inspect your windshield and tires at the same time. 393.78A-WS (Windshield condition defective) appeared in 1,269 shared inspections, and tire violations appeared in 990. A lazy pre-trip that misses a lamp also misses these.
- Verify your emergency equipment. 393.95A1 (no fire extinguisher) and 393.95F (missing warning devices) each appeared on hundreds of the same inspection reports. These are quick checks — confirm both are present and accessible.
- Pay extra attention on Freightliner and Ford equipment. Our inspection records show Freightliner units accounting for 15,796 all-time citations under this code, and Ford units for 8,020. If you are operating either make, your pre-trip lamp check is not optional — it is statistically the highest-risk item on your walk-around.
- Replace lamps proactively, not reactively. A citation at a weigh station adds CSA points even though it will not ground your truck. The 0.0% OOS rate is good news in the short term, but 58,547 citations in the last 12 months means inspectors are actively looking for this defect. Fix it before you pull out of the yard.