2006 Focus Mk2 Tdci Goes Into Limp Mode With Several Fault Messages

[Flying Finn]

First post in the forum as somewhat stuck on the following:

I have a 2006 Ford Focus (Mark 2) TDCi with 67k miles. Fine until recently, but in the last few days whilst driving (usually on the second short drive of the day), the car has gone into "limp" mode with low revs and very limited speed, accompanied by the following messages: Engine system fault, transmission fault, power steering fault - dash lights all go on too.

Sometimes if I leave the car running, the fault clears itself after about 30s to 1 min, and everything is fine thereafter. If I turn the engine off, it will not restart for about 5 mins, and then work fine again. Apart from this the engine sounds just fine and works/accelerates well unless this fault is present.

I have gone through the test function, and it brings up the DTC fault codes 9601, D900 and E510. Thinking it was something to do with the battery, I changed this yesterday and the reading on the test function above shows 11.9V in battery voltage when starting from cold (if that's relevant?).

Has anyone else experienced these symptoms? Any thoughts to what the problem might be?

best regards