393.50A Steering Mechanism Defective — Driver Q&A

Yes, it will in about 6 out of 10 cases. Across our 13 million inspection records, the 393.50A violation was placed out of service 5 times out of 8 citations on file, yielding a 62.5% out-of-service rate. That's roughly double the national average OOS rate of 31.4% across all FMCSR codes. When an inspector finds your steering mechanism defective, broken, or not functioning properly, there's a strong likelihood your truck gets sidelined until you repair it.

This violation carries an 8-point severity weight. CSA points are calculated by multiplying that weight by the number of violations found within a 30-day window. If you receive one 393.50A citation, you'll see 8 points added to your CSA record. If multiple steering defects are cited in the same 30-day period, points stack. Your actual CSA impact depends on how many violations the inspection uncovers and whether other codes are cited alongside it.

Act fast: the steering system is critical to safety and compliance. First, if your truck was placed out of service, you cannot legally operate it until the defect is corrected and re-inspected. Contact a qualified mechanic immediately to diagnose and repair the steering mechanism. Second, document the repair with photos and receipts. Third, request a post-repair inspection at a state DOT facility or certified inspector to clear the out-of-service status. Do not delay—steering defects pose a direct hazard and will block your operation.

Yes—it's significantly more severe than most vehicle maintenance violations. Our data shows 393.50A has a 62.5% out-of-service rate. Compare that to peer codes in the same Vehicle Maintenance category: slack adjuster defects (393.47E) have a 0.0% OOS rate, windshield defects (393.78) are 0.3%, and lighting violations (393.11) sit at 1.8%. Only general inspection/repair failures (396.3(a)(1)) exceed it at 45.3% OOS. Steering is a life-safety system, so inspectors treat defects with urgency.

Yes, you can file a DataQs challenge if you believe the citation was issued in error. The FMCSA's DataQs (Safety Management System Query Tool) lets drivers and carriers dispute roadside inspection records. For a steering defect, your challenge window is typically 90 days from the inspection. Gather evidence: photos of the repair, mechanic's report, or a corrective action showing the steering was actually functional. Equipment-based findings can be challenged if documentation shows the system was compliant at the time. File through the DataQs portal with clear supporting proof.

393.50A is extremely rare across the U.S. Our records show only 3 citations in the last 12 months and 0 in the last 90 days. In the most recent 180-day window, Texas recorded 1 citation. The low volume makes it difficult to identify a geographic hotspot. Nationally, 393.50A ranks #2,269 out of 3,036 FMCSR codes by enforcement volume, so it's uncommon enough that you're unlikely to encounter it unless you have a genuine steering malfunction.

Extremely urgent. The 62.5% out-of-service rate tells you that inspectors place most trucks with steering defects out of service on the spot. You cannot legally haul freight while this violation stands. Additionally, our inspection records show 2 citations in May 2025 and 1 in January 2026—though low overall, when it does appear, the severity is high. Steering failure is a catastrophic safety risk. If cited, repair the defect within 24 hours and get a re-inspection to return to the road.

Both. CSA violations follow the carrier. The citation is recorded against your carrier's USDOT number and appears in the company's Safety Management System profile, where it affects the carrier's CSA scores and safety ratings. However, the underlying safety responsibility is shared: the carrier must maintain the fleet, and the driver must pre-trip inspect and report defects. If you knowingly operated a truck with a defective steering mechanism, that can also trigger personal liability. Always report steering issues to your dispatcher or maintenance team before accepting a load.