— A Mercedes-Benz Sprinter van investigation has been closed after the government found 6,700 reports of rear wheel speed sensors that failed in 2012-2018 Mercedes-Benz and Freightliner Sprinter vans used as campers or recreational vehicles (RVs).
Complaint and warranty data indicates about 99% of rear wheel speed sensor failures are related to moisture intrusion, something that can occur while the vehicles are parked for long periods of time.
If the moisture dries and the rear wheel speed sensor returns to normal operation, the failsafe mode and the warning lights will disappear at the next ignition cycle but the sensor fault code remains stored inside the stability control unit and can be accessed through diagnostics.
A failed wheel speed sensor means drivers cannot apply any torque to the Sprinters and if cruise control is in use it is disabled. Failed rear wheel speed sensors also cause deactivation of the electronic stability and anti-lock brake systems as drivers see multiple illuminated warning lights and messages.
However, some Sprinter drivers reported their vehicles increased in speed when the wheel speed sensors malfunctioned.
Mercedes says there are more than 48,000 model year 2012-2018 Sprinter 3500 vans that were manufactured between January 4, 2012, and October 25, 2018.
The National Highway Traffic Safety Administration closed its investigation after Mercedes announced a recall to replace the rear wheel speed sensors with packaged sensors that allegedly repel moisture.