FMCSR 393.50(c) — Steering Mechanism Defective: Q&A

No. Across our 13 million inspection records, steering mechanism defects cited under 393.50(c) result in an out-of-service order only 1.0% of the time. Of the 1,042 all-time citations for this violation, just 10 trucks were placed out of service while 1,032 were not. This is significantly lower than the 31.4% average out-of-service rate across all FMCSR codes, meaning most inspectors issue this as a non-OOS citation. However, the severity depends on the specific defect—if steering is completely non-functional, an officer may exercise discretion to place the vehicle OOS for safety.

This violation carries a CSA severity weight of 8 points. The total impact on your Safety Management System (SMS) depends on your carrier's overall Safety Fitness Determination and how many similar violations appear in your 12-month rolling window. Within 30 days of the citation, FMCSA applies a multiplier effect—the 8-point weight is factored into your carrier's Vehicle Maintenance BASIC score. If your carrier already has borderline scores, this single citation could push the BASIC into the alert threshold. Consult your carrier's safety department for your specific CSA impact.

1. Document the defect. Note exactly what the inspector found (tie rod loose, steering wheel play, alignment issue, etc.) on your citation.
2. Repair immediately. Do not operate the vehicle unsafely; get the steering mechanism serviced by a certified mechanic before your next trip.
3. Get proof of repair. Obtain a work order and receipt showing the steering system was inspected and corrected.
4. Report to your dispatcher/safety manager. Inform your carrier so they can update your vehicle maintenance record.
5. Keep records for DataQs. If you contest the citation, you'll need photographic or mechanical evidence proving the steering was functional at the time of inspection.

In absolute terms, 393.50(c) is relatively uncommon—ranked #704 out of 3,036 FMCSR codes by citation frequency. Among peer vehicle maintenance violations, steering defects are far less cited than lamp failures (393.9(a) has 660,737 citations) or general inspection violations (396.3(a)(1) has 236,919 citations). However, steering safety is critical: a defective steering mechanism is a direct safety hazard and will result in immediate repair orders. The 1.0% out-of-service rate is low, but CSA weight of 8 is moderate, making this a serious maintenance violation even if it rarely leads to roadside OOS placement.

Yes, you can challenge the citation through the FMCSA's DataQs platform within 90 days of issuance. Contestability depends on the type of finding: if the inspector documented a steering defect (loose tie rod, excessive play, unresponsive movement), you will need solid evidence—photos, a certified mechanic's inspection report, or maintenance records—proving the steering was actually functioning properly at the time of the roadside check. If the citation is based on documentation failure (no proof of recent steering system inspection) rather than observed defect, you may have stronger grounds to contest. Submit your evidence through your carrier's DataQs account or work directly with FMCSA.

Our inspection data shows 1,042 all-time citations for steering mechanism defects. The top carrier receiving this citation is Autotransportes Varela Davila SA de CV with 16 citations (USDOT 1716824), followed by Quality Tank SA de CV with 12 citations. The most commonly cited vehicle make is Freightliner (FRHT) with 181 citations for this violation. However, we do not have state-level breakdowns available in our current dataset. To identify high-citation regions, contact your local DOT or FMCSA field office.

Very urgent. A defective steering mechanism is a direct safety hazard that can cause loss of control, jackknife, or collision. Even though the 1.0% out-of-service rate is low, you should repair the steering system before your next commercial operation. Our records show no citations for this code in the last 90 days, suggesting either improved steering maintenance industry-wide or less frequent roadside inspection for this specific violation. Do not delay repairs hoping the citation is forgotten—FMCSA tracks safety violations, and a second offense for the same defect could result in immediate out-of-service placement or escalated enforcement.

Both. The violation is recorded against your carrier's Safety Management System (SMS) in the Vehicle Maintenance BASIC, which affects the company's SMS profile. However, the roadside inspection record also remains attached to your driver history within FMCSA databases, visible to future employers and auditors. This is why cooperation with your carrier's safety department matters: a single defect citation is manageable, but a pattern of citations—whether for steering or other maintenance issues—can harm both your safety record and your carrier's CSA scores. Prompt repair and documentation protect both parties.