Skip to main content

See also:

Electronic Stability Control Testing: What's Involved

This steering wheel robot controls the steering input for the FMVSS 126 testing procedure.
This steering wheel robot controls the steering input for the FMVSS 126 testing procedure.
Dan Sanchez

Many manufacturers of lift kits and components that raise the ride height of vehicles are putting their latest products through Federal Motor Vehicle Safety Standard Testing (FMVSS 126) that tests the vehicle's ability to utilize its electronic stability controls when used with aftermarket lift kits. The testing utilizes a steering wheel robot that is designed to make quick and abrupt turns at precise angles, to unstabilize the vehicle and allow the stability controls to take over and keep all four wheels on the ground.

Many aftermarket manufacturers of lift kits have undergone testing to prove their products are compliant. According to John Tate, Test Engineer for Link Engineering who conducts the test, there are many variables that allow a vehicle to pass or fail with an aftermarket product on it. Tate explained that the test procedure simply tries to unbalance the vehicle. During the state of instability, if one of the vehicle's wheels is lifted off the ground, it's a no-pass situation.

We were allowed to witness one test at the Ford Proving Grounds in Arizona, where Performance Accessories, a manufacturer of body-lifts were testing a 2014 Chevy Silverado 1500 4x4. The procedure requires mounting a variety of sensors and anti-roll over bars onto the front and rear of the vehicle. A robotic unit is attached to the steering wheel which is calibrated to each vehicle, and accurately sets the degree of steering wheel input. Several tests are done at various speeds and steering wheel input to determine if the vehicle can stabilize itself.

After about 30-45 minutes of testing, the engineers at Link gave the Performance Accessories body-lift kit for the 2014 Silverado a pass, indicating that it works in conjunction with the factory stability control system on the vehicle. "We've always known our body-lift kits do not affect the electronic stability control because we're not swapping out springs, spindles or other components," says Steve Rezek, President at Performance Accessories. "We felt that passing the FMVSS 126 test would add another layer of confidence for our customers, who are spreading the news that you don't need to cut or modify the factory suspension system to add larger diameter tires and achieve the look and off-road performance of a lifted pickup truck."

While many aftermarket lift kit manufacturers have already undergone testing, it shows that most are wanting to be compliant, and show truck owners that its safe to drive a lifted vehicle. For more information on Federal Vehicle Test procedures, visit