2021 Ram ProMaster Reliability Report

Transmission failure is the main pattern here. Vans suddenly lose power at highway speed and drop into limp mode, refuse to shift out of first or into Drive, or lose reverse. One owner lost reverse at 121,000 miles with codes P0736 and P0792. A crash-related report describes a van losing power on a hill, rolling backward with no brakes, and hitting a tree. Other owners report vans rolling while in Park. Fleet operators describe long dealer backlogs and part shortages, and some owners are still waiting on recall parts.

The rearview camera goes black, shows a dim image, or displays a camera-unavailable message in reverse, often on and off. Most reports describe getting a recall notice and then waiting because the dealer has no parts. One owner reports two minor crashes while backing up. Another had a security gateway module replaced twice, and the failure came back both times. Failures show up anywhere from early ownership to about 35,000 miles. One owner of an early-build 2021 van says the van is not covered even though it has the same fault.

A "Service Brake System" warning and the brake light come on during long downhill grades, such as mountain passes. The warning clears only after the van is stopped and shut off. Dealers call it a known issue with no fix, and repairs based on stored codes have not cured it. Owners worry the false warning will hide a real brake fault. A separate pattern involves rear brakes locking up or calipers seizing so a wheel will not turn, often after shifting from reverse to forward. A loud squeal after using the parking brake is also reported.

These reports mostly describe a parts shortage, not mechanical failures. Owners have recall notices for this system and for the rearview camera, but dealers say the repair parts are not yet available. Several owners say the wait has gone on too long. One lost income, and another parked the van after reading the recall letter. One report describes a different problem: the van stalls without warning while driving. Dealers found no fault codes, pointed to the power control module, and did not repair it.

Lug nuts work loose while driving, even after being torqued to spec. Once a few loosen, the remaining studs take the load and shear off. The wheel then wobbles and can separate from the hub, leaving the van undrivable. Most of these reports come from fleet operators running several 3500 cargo vans with the same failure. One separate report describes tread separation on a factory-installed tire at 27,028 miles.

Two reports describe engine-area fires. In one, a van caught fire about twenty minutes after being parked, and the flames spread to a house. In the other, smoke poured from under the hood and through the vents while the van was moving at 40 mph, and the van burned at about 80,000 miles. Cracked cylinder heads that required full engine replacement are also reported at about 80,000 miles, out of warranty. Another owner reports a heavy oil leak at the oil filter because the mounting surface is not flat.

Rear seat belts seize and will not extend or retract. Some lock up during normal driving and then let go under braking. Front seat belt webbing frays, and in one case the dealer replaced both front belts. In motorhome conversions, belts at the dinette or rear seats are too short to fit passengers. Dealers have called that "installed as designed" and declined to fix it.