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.


  • How are you getting these codes?
    – GdD
    Commented Nov 5, 2020 at 8:38
  • Are you sure there's sufficient fuel? Commented Nov 5, 2020 at 10:12
  • Hi the U code is coming from my scan tool(the roadside mechanic had one that showed the same code), the D900 code is coming from the ford test mode on the display. There is 1/4 tank of fuel so that's not a problem, idles perfectly.
    – DamoC
    Commented Nov 5, 2020 at 18:31

1 Answer 1


Although you have probably fixed the error, maybe someone comes here with the similar symptom.

First of all, if "Engine malfunction" message was shown, the error had to be stored in the PCM. U-codes won't cause that. In this generation, Ford uses HS-CAN and MS-CAN for communication with modules so there is a possibility you are not getting all of the errors.

That lack of power caused the engine to die or not respond to the accelerator pedal, or it just reduced the power so you can go up to about 50 mph?

If the former, I'd look into crankshaft position sensor or cluster panel malfunction (cracked soldering). If the latter, well, there are many possibilities - from burnt up glow plugs (but then you'll have MIL error on your dashboard), clogged or damaged EGR valve or many other problems.

Everything comes down to reading the errors on Ford dedicated cable and software.

  • 1
    Thanks, if I remember correctly it wouldn't even go around 50. It has been sorted now though. I got a cable and forscan and it came up with fuel pressure and o2 sensor issue. Changed the fuel filter and it's been fine since.
    – DamoC
    Commented Mar 12, 2021 at 11:18

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