NHTSA Complaint #11712817 — 2025 RAM 2500

While driving in 4x4 on a snow covered road, the truck simultaneously got a check engine light as well as several other error messages to include service required to the emergency braking and the trailer brake controller. At the same time, the full exhaust brake engaged without any driver input and caused a sudden slowing of the truck's tires on a slippery surface. The owners manual specifically warns "Do not use the exhaust brake feature when driving in icy or slippery conditions as the increased engine braking can cause the rear wheels to slide and the vehicle to swing around with the possible loss of vehicle control, which may cause a collision possibly resulting in personal injury or death." Fortunately I had a lot of weight in the truck when this happened and I was able to control it, but a malfunction that turns on the full exhaust brake, especially while 4x4 is engaged, is dangerous enough that there is a warning in the manual. This happened twice. I had a solid check engine light on, and the following day while waiting for a service appointment, a slew of new warnings were flashing across the screen, locking the transmission in 6th gear, advising the 4x4 was no longer available, and may others. I attempted to shift from drive to reverse, the gear shifter locked itself in park. I shut the truck off to try restarting it and moving it, but there was no power getting to the truck to use the sos button to call for help in a poor cell reception area, no lighting worked while obstructing half of a travel lane on the roadway. The truck had good voltage prior to this. The truck was towed to the dealer with 5100 miles on it.