2016 328i Xdrive - U1408 and P0128
I purchased a 2016 328i Xdrive with 37,200kms. After a few weeks I got a check engine light. It took some time to get an appointment at the dealer but there was one time where I felt a loss of power. When I floored the gas I got no throttle response. When I scanned for codes I got P0128 and U1408. I finally took it to the dealer and they found a faulty thermostat and replaced it with a BMW OEM unit.
Today on the way to work I suffered another loss of power on the highway. No check engine light went on but I finished my drive to work. When I parked the car I could hear the fans running loudly. When I got into the car at the end of the day and started it, I got another check engine light on the dash. I scanned with my scanner and got P0128 and U1408 again.
This doesn't look like a thermostat to me. What's weird is I used Bimmerlink early to measure the lower rad hose temp and found it abnormally low. Could a defective lower rad hose coolant temp sensor cause these issues? It was reading 0-20 deg C after quite a lot of driving.
Does anyone know what U1408 means? I used Bimmerlink to scan and it only found one "Permanent Error" in the "Electronic Transmission Management" the hex code was FFCF2D and it says "No Description Available"
I'm going to take it to the dealer again but any had something like this before?