What 178.341-5A2 means in plain language
FMCSR 178.341-5A2 governs the remote control shutoff mechanism required on MC306 cargo tanks. An MC306 is a specialized tanker truck designed to haul liquid hazardous materials—gasoline, diesel, other flammable liquids, and corrosive substances. The remote shutoff is a safety device that allows the driver or an authorized person to stop the flow of product from the tank in an emergency without having to physically access the cargo area or valve.
This regulation requires that the remote shutoff system be properly installed, functional, and maintained. If an inspector finds that your MC306 lacks a working remote shutoff, or that the device is damaged, inaccessible, or not correctly positioned, you will be cited for this violation. The intent is straightforward: in a spill, leak, or emergency, the driver must be able to stop product discharge quickly and safely.
Compliance means your MC306 must have a remote shutoff that is mechanically sound, clearly labeled or identified, and within reach of the driver during normal operation. Any deterioration, modification, or non-functionality of this system is a violation.
What our enforcement data actually shows
Across our 13 million+ inspection records, 178.341-5A2 has been cited only 1 time in our all-time dataset, with that single citation occurring in the last 12 months. In the last 90 days, we have recorded 0 citations. This code ranks #2796 out of 3,036 FMCSR codes by citation volume, making it exceptionally uncommon in roadside enforcement.
The out-of-service rate for this violation is 0.0%—the single citation on record resulted in the vehicle remaining in service. By comparison, the all-FMCSR average out-of-service rate is 31.4%, which means inspectors place violators out of service in roughly one-third of all hazmat-related stops. The near-zero enforcement volume and zero OOS rate for 178.341-5A2 suggest that either MC306 remote shutoff systems are very reliably maintained in the field, or inspectors encounter defects in this component only rarely.
Who gets cited most
Our enforcement records show that TRANSPORTACION CARRETERA SA DE CV (USDOT 3100833) received the single citation for this code. Because the overall citation count is 1, geographic and fleet-level variation is not meaningful in this dataset. The citation was recorded in June 2025. No state-by-state or multi-carrier pattern is available.
How severe is this compared to similar codes
Within the Hazardous Materials category, 178.341-5A2 is far less frequently cited than related loading, placarding, and packaging violations. For context:
- 177.834A-HMC (General loading/unloading hazmat) has 3,954 citations with a 99.2% out-of-service rate—nearly all violators are pulled off the road immediately.
- 177.834(a) (General loading/unloading hazmat) has 3,839 citations and a 97.9% out-of-service rate.
- 177.817(a) (Placarding violation) has 2,274 citations and a 75.1% out-of-service rate.
- 172.602(c)(1) (Maintenance/accessibility of Emergency Response information) has 1,464 citations but a 0.0% out-of-service rate, matching the OOS rate for 178.341-5A2.
The remote shutoff code is dramatically less common in enforcement. When it does appear, it does not automatically trigger an out-of-service order, suggesting that inspectors may treat it as a deficiency that can be remedied quickly or that the violation itself is not deemed an immediate safety hazard warranting removal from service.
How to avoid it
MC306 remote shutoff violations are rare, but they are preventable with basic pre-trip discipline:
- Before every shift, test your remote shutoff. Access it from the driver's position, activate it (or visually confirm it moves freely), and ensure it returns to neutral. Do not assume it works—actually verify it.
- Inspect for visible damage or corrosion. Look for cracks, rust, bent linkages, or disconnected cables. Remote shutoffs on tankers are often exposed to weather and road spray; they deteriorate over time.
- Confirm accessibility. The shutoff must be reachable from the driver's seat or step without climbing over the tank or reaching into confined spaces. If you have modified your truck or added equipment, ensure the shutoff is not blocked.
- Document your pre-trip check. Record the date, time, and condition of the shutoff in your vehicle inspection report or maintenance log. This creates a record that you are actively maintaining the system.
- Report defects immediately. If the shutoff is stuck, damaged, or inoperable, do not haul hazmat. Report it to your dispatcher and motor carrier's maintenance department. Driving a non-compliant MC306 is not worth the citation and potential safety risk.
- Know your truck's design. If you operate a KW (Kenworth) or other make, familiarize yourself with where the remote shutoff is located and how it is accessed on that specific model. Design varies by manufacturer and model year.
The good news: this violation is extremely rare in the field, which means most drivers and carriers have this system working correctly. Consistent pre-trip verification and prompt reporting of mechanical issues will keep you compliant.