Ford Focus 2010 1.6 'Engine malfunction' warning and no power

Driving today was fine for maybe a mile until I joined the motorway(highway). Once I was building up speed it came up with ‘engine malfunction’ on the display with the alarm sound and then started lacking in power. I geared down but power kept on dropping.

I then turned the engine off and back on, it started driving fine for a second or two before the lack of power kicked back in.

There is no CEL on the dash displaying and no other warning lights/symptoms.

I used recovery to get back home.

Now the only DTC is a Ford D900 or a U0073 (canbus A communication fault). It has been fine for the past 350 miles (how long I’ve had it and had this error code for).

Any insight/theories/help appreciated. Apart from the issue today the car drives fine.

Cheers