FMCSR 393.201B: Loose Cab Bolts — Citations & OOS Risk

No—this citation alone will not automatically ground your truck. Across our inspection records, 393.201B results in an out-of-service placement only 5.9% of the time (17 out of 286 all-time citations). That's significantly lower than the 31.4% average across all FMCSR codes, meaning inspectors typically issue this as a violation without immediate removal from service. However, if loose cab bolts are paired with other structural or safety defects during the same inspection, an OOS decision becomes more likely.

393.201B is a relatively low-frequency citation—ranked #1104 of 3,036 FMCSR codes by total volume. In the last 12 months alone, we recorded 168 citations nationally. While not a severe violation that automatically sidelines your rig, loose or missing cab bolts are a structural integrity issue that inspectors will expect you to correct. Compared to peer codes in vehicle maintenance, 393.201B sits well below the OOS rates of codes like general inspection/repair (45.3%) and defective slack adjusters (0.0%), making it a correctable finding rather than an immediate safety crisis.

First, document the exact bolts cited and their location on the cab. Second, have a certified technician inspect the entire cab mounting system—not just the flagged bolts—to identify if corrosion, fatigue, or impact damage is systemic. Third, check your vehicle for co-occurring issues: our data shows 393.201B frequently appears with inoperable lamps (393.9, 14 shared inspections in the last 90 days), missing emergency equipment (393.95A and 393.95F, 5 shared each), and brake defects (393.45D, 4 shared). Complete repairs within your jurisdiction's timeline and request re-inspection if needed. Keep copies of all work orders and photographs of repairs.

Illinois leads with 42 citations in the last 180 days (2.4% OOS rate), followed by Texas with 28 citations and a higher 10.7% OOS rate. New Mexico ranks third with 9 citations (0.0% OOS rate). The concentration in Illinois and Texas suggests geographic clusters—likely driven by inspection intensity, weather exposure (corrosion), or carrier density in those states. If you operate primarily in Illinois or Texas, stay vigilant during pre-trip inspections.

Citations are steady but episodic. In the last 12 months, we recorded 168 citations (average ~14 per month). Looking at the trend, July 2025 was the busiest month with 22 citations, while April 2026 saw just 1. The last 90 days (January–April 2026) show 36 citations total—suggesting enforcement remains active but not accelerating. This is a maintenance issue that appears to spike seasonally, possibly tied to road conditions or inspection campaign cycles rather than a dramatic enforcement surge.

393.201B is minor compared to its structural peer, 393.201A (frame cracked/loose/broken), which frequently appears in the same inspections (4 shared citations in the last 90 days). While both are frame-related, 393.201B targets the fasteners securing the cab specifically. The data shows 393.201B is treated less severely than general mechanical failures—its 5.9% OOS rate is a fraction of the 45.3% rate for general inspection/repair violations (396.3(a)(1)). Consider it a maintenance correction rather than a structural emergency.

Yes, you can file a DataQs (Roadside Data Quality and Safety) challenge to FMCSA if you believe the citation is inaccurate or unwarranted. DataQs is the formal process for drivers and carriers to dispute inspection records. For 393.201B, contestability depends on whether the inspector correctly identified loose or missing bolts—this is an objective, observable condition. If you have photographic evidence that bolts were secure, tight, or not actually missing at the time of inspection, that evidence strengthens a DataQs filing. Submit your challenge within 90 days of the inspection date through the FMCSA DataQs portal.

Freightliners dominate, accounting for 81 of 286 all-time citations (28%), followed by International trucks with 41 citations. Hino, Kenworth, and Mack round out the top five. The prevalence on Freightliners suggests either higher exposure (more Freightliners on the road) or a design pattern where cab bolt corrosion or loosening is more common. If you drive a Freightliner, International, or Hino, prioritize cab bolt inspections every 100,000 miles or at minimum before long hauls.