Rear Wheel Speed Sensor Failure

The Office of Defects Investigation (ODI) analyzed complaint data provided by Daimler Vans USA, LLC (Daimler) as well as complaints submitted to ODI from consumers to identify incidents related to Rear Wheel Speed Sensors (RWSS) failures. ODI's analysis identified 6,710 incidents of RWSS failure (unique VINs) in MY 2012-2018 Mercedes- Benz and Freightliner Sprinter vehicles upfitted to campers or recreational vehicles (RVs) representing 81 percent of all Sprinter RWSS reports. Complaint and warranty analysis indicated that the majority of incidents (approximately 99%) were related to RWSS moisture intrusion condition in the Sprinter 3500 5-ton variant, which accounts for 98 percent of upfit campers, where moisture build-up and crystal dendrite formation develop in parked RVs and lead to sensor failures. According to the Daimler Information Request (IR) response, if the wheel speed information is detected as implausible by the Electronic Stability Program (ESP) control unit, the ESP system enters a failsafe mode where: - Driver torque requests are no longer accepted; - Cruise control, if used, would be deactivated; - The ESP/ABS system shuts off; and - Multiple warning lamps and messages advise the operator to take the vehicle to the workshop. While the majority of reports involved only ABS and/or ESP warning lights and messages on the instrument cluster due to faulty sensor signals triggering a failsafe mode, some reports cited intermittent sensor failures resulting in increased vehicle speed while in cruise control and degraded ABS or ESP. Degraded ESP functionality may impact driving stability of the 5-ton vehicle. On Feb 3, 2021, following discussion with ODI, Daimler submitted a Defect Information Report (DIR) to NHTSA describing a defect in the RWSS disabling the ESP control unit functions in approximately 48,667 MY 2012 through 2018 Mercedes-Benz and Freightliner Sprinter 3500 vehicles manufactured from Jan 4, 2012 through Oct 25, 2018 (Recall 21V-042). In its