NHTSA Complaint #11675984 — 2025 WINNEBAGO EKKO

On [XXX] while driving my 2025 Winnebago Ekko 23B at elevations between 5,000 and 6,000 feet, the vehicle repeatedly lost engine power and stalled under specific conditions, creating a significant safety hazard. The issue occurred when the house batteries were below 100% charge, the engine was at idle or low RPM (below 1,250), and the secondary alternator began charging the Lithionics battery system, causing RPMs to drop below 500, complete loss of propulsion (unable to move forward or reverse), and occasional activation of the check engine light with codes P0506, P3002E6, and P30059B. This happened four times, including twice when attempting to pull out from stops, which could have resulted in a collision if traffic had been present—imagine suddenly stalling in an intersection with family aboard. The problem resolved at lower elevations (below 2,000 feet) or when maintaining higher RPMs before charging initiated, but it was reproducible every time the conditions were met at altitude. Despite diagnostics at a Mercedes-Benz dealership , where systems were cleared and no faults found (suspecting the Winnebago-installed secondary alternator), and repairs at the Winnebago Factory Service Center in Forest City, IA , where the Wakespeed regulator was unnecessarily replaced and the issue blamed on Mercedes (suggesting an unsubstantiated "learning mode" at elevation), the root cause remains unaddressed. This defect, reported by multiple other Ekko owners in online forums and directly to Winnebago, violates Mercedes upfitting guidelines against drawing alternator power below 1,200 RPM and poses an ongoing risk of sudden power loss in traffic or on highways. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)