The check-engine light came on my 2nd day of ownership (less than 100 miles driven by me, but 2032 miles on it when purchased new - RV conversion from Entegra Coach through LaMesa RV), on October 5, 2025. After diagnosis at a Ram dealership (Larry Miller Dodge Ram in Tucson AZ), they identified the code was misfire on cylinder 6, which caused low compression, with a root cause of the intake valves being improperly seated during manufacturing. The dealership replaced some cylinder and engine parts, but the issue recurred on Cylinder 4 after driving it about 5000+ miles, on June 13, 2026. Again, misfire check-engine code and loss of compression on cylinder 4. The engine ran very rough and had loss of power. The engine is still under investigation by another Ram dealership service department (Crest Auto World, Center Conway, NH). I have learned that loss of compression can cause the engine to stall, lose acceleration power (which it did), and potentially throw a rod and blow a hole in the engine. Since this was caused by a manufacturing defect, I am also concerned that there are other vans with this issue on the road.

Source: NHTSA complaint ODI #11753738 · view all complaints for this vehicle at nhtsa.gov

whenever I was driving on the highway at 80MPH it felt like someone stepped on the brake pedal abruptly for a split second and the car with squiggly lines behind it appeared on the instrument panel, then disappeared. Goin this fast and having that happen is a major safety issue. After this happened the steering felt all over the place like I was floating and if I turned the wheel just a tiny bit the vehicle thought I turned it a lot and over corrected, needless to say I was all over the highway. Then the backup camera stopped working, the screen was completely black. I reset the screen and it worked for a couple seconds but then the color and picture got very distorted and then again went to a black screen.

Source: NHTSA complaint ODI #11743511 · view all complaints for this vehicle at nhtsa.gov

Office of Defects Investigation National Highway Traffic Safety Administration 1200 New Jersey Avenue SE Washington, DC 20590 Re: Safety Defect Complaint — Ram ProMaster (2018–2025) — Cowl Water Intrusion into Engine Compartment To Whom It May Concern, I am writing to formally report what I believe to be a serious, systemic, and unresolved design defect in the Ram ProMaster van, affecting model years 2018 through at least 2025. I am requesting that the Office of Defects Investigation open or expand a formal investigation into this matter. Nature of the Defect: The windshield cowl on the Ram ProMaster is designed in a manner that permits significant water intrusion directly into the engine compartment. Water enters through the cowl seam and surrounding gaps, bypassing any drainage system, and flows onto critical engine and electrical components including but not limited to: the serpentine belt and pulley system, the engine fuse box, transmission components, and wiring harnesses. I brought my vehicle to two separate authorized Ram dealerships. The second dealer confirmed — based on testing conducted on multiple ProMaster vans dating back to 2018 — that this water intrusion behavior is consistent across the model line. In other words, the dealer has effectively confirmed that this is not a defect isolated to my vehicle, but a design characteristic of the ProMaster platform itself. This confirmation does not reassure me. It alarms me. A design that has permitted consistent water intrusion onto safety-critical engine and electrical components across a major commercial vehicle platform for over a decade is not an acceptable engineering standard. Given the size and weight of these vehicles — many operated commercially and carrying passengers or heavy cargo — the consequences of power steering loss, electrical failure, or mechanical failure are severe. We have tried dealing with Stellantis as well. Any help would be greatly appreciated. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Source: NHTSA complaint ODI #11728215 · view all complaints for this vehicle at nhtsa.gov