FMCSR 393.9B-LPL: Parking Lamp Obscured – Driver Q&A

No. Across our 13 million inspection records, this violation has never resulted in an out-of-service placement. All 37 all-time citations for obscured parking lamps were non-OOS findings. The 0.0% out-of-service rate for 393.9B-LPL is significantly lower than the 31.4% national average across all FMCSR codes, making this a minor equipment citation rather than a safety-critical violation that would immediately ground your truck.

First, document the citation details and inspect your parking lamp assembly for obstruction—dirt, damage, or misalignment. Our inspection records show that when 393.9B-LPL appears, it often co-occurs with turn signal obscuration issues (2 shared inspections in the last 90 days) and lack of proof of periodic inspection (2 shared inspections). So also check: (1) your proof of inspection documentation, (2) all signal and marker lights for dirt or damage, and (3) your pre-trip inspection checklist compliance. Clean or repair the lamp and photograph the fix for your records.

It's relatively minor. Our database ranks 393.9B-LPL #1717 out of 3,036 FMCSR codes by enforcement volume, with only 37 all-time citations and a 0.0% OOS rate. By contrast, the broader code 393.9 (inoperable required lamps) has generated 180,097 citations with a 6.9% OOS rate, and 393.9(a) shows 660,737 citations with a 15.4% OOS rate. Obscured parking lamps are treated as a compliance defect but not a functional safety failure, so it carries much lower enforcement weight than inoperable lamps.

Citation volume is stable but low. Our records show 19 citations in the last 12 months and 4 in the last 90 days. Monthly trend data indicates sporadic enforcement: 3 citations in December 2025, 4 in September 2025, but zero in July and August 2025. This is not a high-enforcement violation, and the 90-day count suggests it is not an emerging priority for roadside inspectors.

Pennsylvania leads by a significant margin. In the last 180 days, our inspection records show Pennsylvania with 3 citations, followed by Nevada with 2 citations. Connecticut, Kansas, New Jersey, Alabama, South Carolina, and Arizona each had 1 citation. If you operate primarily in the Northeast or Southwest, be slightly more vigilant about lamp cleanliness and condition, but this is not a regional hotspot for enforcement.

There is no federal "cure period" built into FMCSR, but because 393.9B-LPL does not trigger out-of-service status, you should repair it as part of routine vehicle maintenance within your next pre-trip inspection cycle—typically before your next haul. The violation reflects a maintenance oversight rather than an emergency safety risk. However, if you receive a second citation before correcting the first, you may face escalated enforcement action or fleet safety audits. Repair promptly to stay clean.

Yes, you can submit a DataQs (Roadside Inspection Report) challenge if you believe the citation was issued in error. Because obscured parking lamps are a visual, equipment-based finding (not a behavioral violation), contestation is most effective if: (1) the lamp was not actually obscured at the time of inspection, (2) you have photographic evidence of the lamp's condition, or (3) you can show the obstruction was caused by road debris or environmental factors beyond your control during that inspection event. Submit your challenge through the FMCSA DataQs portal with supporting photos.

Quality Tank SA de CV (USDOT 2864600) has the highest citation count with 4 all-time citations for obscured parking lamps. All other carriers in our database show only 1 citation each. This suggests the violation is widely distributed across the industry rather than concentrated in a few fleets, and does not indicate a systemic compliance problem at any single carrier.