What 393.22B-LPL means in plain language
This citation addresses the combination of lighting devices on your truck. The regulation requires that lamps installed on commercial vehicles must be compatible and function together as designed—no mixing incompatible lamp types, no jury-rigging brightness levels, and no combining lighting systems that don't belong together.
In practice, inspectors flag this violation when they find lamps that don't match the original equipment specification, such as mismatched headlight bulb types, improper auxiliary lighting wired into primary circuits, or LED bulbs retrofitted into housings designed for incandescent units. The goal is safety: uniform lighting ensures visibility for you and other road users, and prevents electrical faults.
What our enforcement data actually shows
Across our 13 million inspection records, 393.22B-LPL is a low-enforcement-volume citation. We've recorded 373 all-time citations, with 227 in the last 12 months and 51 in the last 90 days. The code ranks #1016 out of 3,036 FMCSR codes by citation frequency.
Most importantly: this citation almost never results in out-of-service status. Our data shows a 0.3% OOS rate across all 393.22B-LPL citations—meaning only 1 truck out of 372 was placed out of service. This is dramatically lower than the all-FMCSR average OOS rate of 31.4%. In practical terms, if you receive this citation, you can expect to continue your route in the vast majority of cases. The inspection will document the violation, but it is not an emergency safety stop.
Monthly enforcement has been steady but variable. Over the last 12 months, citations peaked at 27 in both May and June 2025, dipped to as low as 1 in April 2026, and have averaged around 16 per month.
Who gets cited most
Our inspection records show state-level concentration in three jurisdictions. California leads by a significant margin with 44 citations over the last 180 days, followed by Pennsylvania with 14, and Missouri with 7. All three states maintain a 0.0% OOS rate, consistent with the national pattern for this code.
At the carrier level, our data shows fleets such as San Juan Unified School District with 6 citations across all time, and Carmel Towing and Garage Inc with 3 citations. This code appears sporadically across the carrier base rather than clustering in any single fleet type, suggesting it is an equipment-specific issue rather than a systemic compliance problem in any particular segment.
Vehicle makes cited most frequently include Freightliner (66 citations), Kenworth (37 citations), and Peterbilt (30 citations)—the typical heavy-duty tractor makes dominate simply because they represent the largest population of long-haul trucks on the road.
How severe is this compared to similar codes
Lighting-related violations fall into a broader Vehicle Maintenance category. When we compare 393.22B-LPL to similar codes, the contrast is stark:
393.9(a) — Inoperable required lamps has generated 660,737 citations with a 15.4% OOS rate. That code addresses lamps that don't work at all; it is far more common and carries meaningful enforcement severity.
393.11 — Lighting devices/reflectors accounts for 179,734 citations with a 1.8% OOS rate. That broader lighting standard is cited much more frequently but still results in out-of-service status only occasionally.
393.78 — Windshield condition defective shows 157,894 citations and a 0.3% OOS rate—matching 393.22B-LPL's OOS frequency, suggesting both are typically minor compliance documentation issues.
The key takeaway: 393.22B-LPL is a low-volume, low-severity citation. It documents a configuration problem but does not trigger the safety intervention that inoperable lamp codes do.
How to avoid it
Our data reveals some patterns worth acting on:
1. Stick to OEM lighting specifications during pre-trip inspection. Before you depart, visually confirm that all headlights, taillights, marker lights, and auxiliary lamps match the vehicle's original equipment design. If you've recently serviced or repaired lighting, verify the replacement bulbs or modules are the exact type specified in your truck's manual. Mismatches are the primary trigger for this citation.
2. Do not retrofit LED or HID upgrades into housings not rated for them. Aftermarket brightness upgrades are common, but they create electrical and optical incompatibilities. If you want upgraded lighting, use complete replacement kits engineered for your vehicle model, not piecemeal substitutions.
3. Check for loose or improperly wired auxiliary lights. Our co-occurring violation data shows that 393.22B-LPL frequently appears alongside inoperable lamp codes (393.9A variants appeared in 4 shared inspections in the last 90 days). Wiring failures and jury-rigged connections lead to both lamp combination issues and outright lamp failure. During pre-trip, look for visible damage, corrosion, or loose connectors in light housings.
4. Address electrical faults immediately. The same co-occurring data indicates that fatigue-related citations (392.2 variants) appeared in 12 shared inspections with 393.22B-LPL in the last 90 days—not because fatigue causes lighting issues, but because improperly maintained vehicles correlate with multiple safety deficiencies. A well-maintained truck is less likely to develop lamp combination problems.
5. Document your lighting maintenance. Keep records of any bulb replacements or light repairs you perform. This creates a clear timeline showing you are using OEM parts and following specifications, which is your best defense if an inspector questions a light configuration during a roadside check.