2017 Ford Expedition EL power train problems

“For 1.5+ years, the transmission will unexpectedly and suddenly downshift into 1st gear without warning. Which causes a sudden deceleration. No warning lights before it happens. It occurs randomly and at different speeds. It has happened over 20 times. I've experienced it happening at speed ranging from 35mph to 65mph. The gear shifter was in the drive position each time this issue occurred. The suv is the 2017 ford expedition EL with the 3.5L ecoboost engine with 6 speed automatic transmission. No check engine light before or after the issue (so no OBD2 code to read) a big yellow warning appears during/after saying "see manual". Sometimes the issue will resolve in a few seconds. The suv has not been to the dealership yet for this issue. But i will be contacting ford today.”

“The contact owns a 2017 Ford Expedition. The contact stated while attempting to start the vehicle, the vehicle failed to start. Roadside Assistance was contacted. The technician connected the battery cables and jumpstarted the vehicle. The vehicle was started, and the vehicle was driven to the residence. The contact later replaced the battery. The contact stated that the failure reoccurred. The vehicle was taken to the dealer where it was diagnosed with parasitic battery drain due to a failed gear shifter. The contact was informed that the gear shifter needed to be replaced. The vehicle was being repaired. The contact was informed that parts had been ordered for the repair. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 40,000.”

“I can be driving up a hill the traction control warning light and hill decent braking light come on causing the vehicle speed to drop the vehicle shakes acting like it is trying to stop. Once you stop and turn the vehicle off the error codes go away . This problem has been occurring since early September it currently only occurs going up hill on one road”

“While driving, the speedometer began to bounce around. This caused erratic shifting. At one point the speedometer went to zero while we were still moving. I pulled over put it in park and it would not go into gear. During this the air bag light came on. After turning the vehicle off and back on again, everything went back to normal. Over a period of days, it would do the same thing again, but not as bad as the time listed above. The speedometer will bounce around while driving and cause moderate shifting issues. I took the vehicle into a shop, and they ran the code as being Output Speed Sensor. After research, it appears Ford had a recall on output speed sensors for 2014 F-150 vehicles (Recall Reference Number 24S37) which use the 6R80 transmission. I contacted my local Ford dealership and Ford corporate via chat, and both told me my 2017 Expedition was not covered under that recall. Since my vehicle uses the same transmission, I inquired as to what they did to fix the output speed sensor issue. They could not provide me with that information. I have several videos of the speedometer bouncing around, but am unable to upload them here.”

“In 2022, around mileage of 67000, our SUV was climbing a steep road when it suddenly made a pop sound & went into limp mode with the wrench light showing and the engine sounding rough. It felt like no fuel was getting to the engine & the gas pedal was non-responsive. The RPMs didn't change when the gas pedal was pressed. The grade was so steep, we barely made it to the side of the road without rolling backwards into traffic behind us. After turning the engine off and sitting about 10 mins, we tried starting the engine again. The car seemed to have reset itself! It ran fine; the wrench light turned off, and the gas pedal was responsive again. (At the time, we were on vacation at the coast and had traveled from our home at about elevation 3500'. We had also recently had to buy gas from a small no name gas station, so we feared we may have gotten bad fuel). From there, we returned home without re-occurrence, and we used fuel cleaning additive to our Chevron fuel for the next 2 fill ups. Then, approximately 600 miles later on a flat grade, it happened again without the pop sound. We immediately went to our Ford dealer who found no error code but found our purge…”

“The contact owns a 2017 Ford Expedition. The contact stated while driving approximately 50 MPH, the transmission unexpectedly downshifted to first gear, causing the vehicle to abruptly slow down. The contact stated that after restarting the vehicle, the failure was corrected. The vehicle was driven to the local dealer who diagnosed the vehicle and determined that the transmission lead frame was faulty and needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure, but no assistance was offered. The failure mileage was 170,000.”