NHTSA Complaint #11599190 — 2023 NEWMAR DUTCH STAR

I experienced unintended collision braking with dash warnings flashing. I was trying to accelerate from a side street onto a two-lane state highway. The motorhome came to a complete stop after getting up to about 30-35 MPH. After an extraordinarily long minute or so I was able to accelerate a second time and the motorhome did unintended braking a second time! It was very scary because I was blocking a busy highway in one direction, and I was not sure what to do. I finally turned the engine off, turned the ignition key on, and waited to make sure the engine and dash system completely rebooted before starting the engine (this is what I normally do). I was then able to accelerate up to speed. The vehicles behind me had to brake hard to avoid running into my motorhome during the collision braking, they then had a challenging time passing me safely due to my generous size, and my stress level was extremely high. By coincidence I was taking the motorhome to be serviced for other items that morning. While on my way to the dealership a CMS Fault warning was displayed for the first time. I safely stopped the motorhome at a rest stop and restarted the engine. This turned the CMS Fault warning off. The Newmar dealer is to diagnosis the problem with Newmar's technical support. I have not picked up my motorhome as of July 5, 2024, so I do not know if the CMS Fault is fixed. I did not get any warnings before the unintended braking, only the CMS Fault warning afterwards. I do not know what fault codes the dealership may have read in the CMS control module, and I do not know if the dealership has replaced or adjusted any components at this time.