4Front School Bus

A: 4Front is an advanced frontal airbag system for Fire Trucks, Commercial Trucks, and School Buses that includes a sensor (Fire/Truck/Bus), buckle pretensioner (Fire), seat pull-down system(Fire), steering wheel airbag (Fire/Truck/Bus) and optional knee bolster airbags (Fire).

A: A sensor inside the cab monitors the vehicle’s longitudinal and lateral accelerations. If the sensor detects a frontal crash of significant magnitude, it sends a signal that inflates a steering wheel airbag to protect the head and neck of the driver.

A: Location of the sensor is dependent on OEM and vehicle model.

A: The 4Front steering wheel airbag is specifically designed for commercial vehicles. While passenger car airbags deploy primarily in a horizontal trajectory toward the driver, the 4Front airbag deploys vertically (toward the vehicle’s roof) while expanding outwardly at the same time. The reduced height-to-diameter ratio is designed to protect the driver’s chest from the wheel rim while also affording head and neck protection.

A: Vehicles have been dynamically tested to show that when the seat belt is properly worn, the passenger ATD does not contact the dash.

A: Yes, the system will deploy regardless of whether the driver is wearing a seat belt. However, the 4Front system relies on seat belts as its core restraining device. Although unbelted passengers may be afforded some protection by the airbags, unrestrained occupants are not safe in a crash, and it is important that all vehicle occupants are seated and belted at all times.

A: The airbags fill with a non-toxic gas mixture comprised mostly of argon.

A: 4Front employs pyrotechnic components to activate the steering wheel airbag and knee bolster airbag. When the frontal sensor sends a signal, a small charge is used to activate these components resulting in the smoke you see.

A: 4Front airbags are designed to rapidly deflate in order to properly manage the energy imparted by the decelerating driver. For this reason, the steering wheel bag is vented and will deflate in less than a quarter of a second after initial impact.

A: Yes, 4Front is live until the system has deployed.

A: No, 4Front is engineered into specific cabs and must be validated through a series of barrier tests before being made available on a truck platform.

A: Please contact IMMI for information on the cost of 4Front.

A: If the system is inoperable, a fault light on the dash will remain on while you’re driving. A diagnostic tool is now available that reads all system faults and displays them in a graphical format.

A: For your own safety, 4Front components are designed for one use. If your vehicle is involved in a rollover, the 4Front system must be replaced. Do not attempt to repair or restore any damaged components yourself.

A: The 4Front system has a 15-year service life. Contact IMMI for more warranty information.

A: There are currently no Federal Motor Vehicle Safety Standards (FMVSS) that require anything more than a two-point belt for vehicles weighing more than 8,500 pounds. 4Front was developed with the guidance of Society of Automotive Engineers (SAE) standards for the design, manufacturing, operation and maintenance of commercial vehicles.