FMVSS 126: Electronic Stability Control (ESC) And Brake Repair

Do you realize that every 2013 model year car and truck (under 10,000 lbs.) has been equipped with stability control as a standard feature? The mandate was made by the National Highway and Traffic Safety Administration (NHTSA) with Federal Motor Vehicle Safety Standard (FMVSS) 126. NHTSA has estimated FMVSS 126 has saved between 1,536 and 2,211 lives a year by preventing accidents and rollovers.

Since September 1, 2012, every light car and truck manufactured or imported in the U.S.  has been equipped with Electronic Stability Control (ESC) to comply with Federal Motor Vehicle Safety Standard (FMVSS 126).

FMVSS 126 was first proposed in 2004, and is probably one of the best standards in the book because NHTSA consulted not only OEMs, but the aftermarket. FMVSS 126 was so well researched that in 2008 they also projected vehicle costs would be no more than $380 for anti-lock brakes and an additional $111 for electronic stability control.

ESC systems use the brakes to control the attitude, weight transfer and overall traction of a vehicle in case of an emergency. The system pulses or releases the brakes individually and controls engine torque to achieve the best correction.

The test for FMVSS 126 is “technology-neutral” and basically involves placing a robotic system in the vehicle that performs a series of maneuvers that can make a vehicle unstable. Sensors then measure how well the ESC system corrected the condition. It does not test individual components but the vehicle as a whole.

FMVSS 126 requires vehicles modified by aftermarket accessories and add-ons to still meet the performance requirements of the regulation. In a nutshell, if a product affects vehicle acceleration, deceleration or handling, it needs to be tested. Even aftermarket products for appearance (lowered suspension, low profile tires, etc.) or convenience (roof racks, etc.) may need to be evaluated for their compatibility with a vehicle’s active safety systems. This is a new twist to FMVSS standards that typically targeted a new vehicle and not the aftermarket.

The new regulation also specifies that stability control systems can’t be disabled by shops, only the owner of the vehicle can do that. What does this mean for regular replacement parts and brake pad manufacturers? It could mean more testing and expense if the new standard is enforced to its full extent. After all, brake pads and rotors are at the heart of any ESC system.

Some friction material suppliers are jointly developing test standards and procedures along with SAE for friction materials that could make testing less expensive and more consistent. But, NHTSA still has not required or tried to enforce FMVSS standards on brake pads.

For shops servicing brakes, you are not off the hook. Since the performance of the stability control system comes down to the performance of the foundation brake system, not returning it to “like new” condition or better will compromise the ability of the system to correct the dynamics of the vehicle in a panic situation.