Focus 1.8TDCi possible fuel pump issue

I have an '04 Focus 1.8TDCi, 191,000 miles, brilliant car. A few days after its MOT while driving home from work on a dual carriageway at 60mph the glow plug light started flashing, the car went into limp mode and then switched off completely a few seconds later. After a couple of minutes it started back up and has been fine since. I had the fault codes read and there was an issue with the throttle position sensor, which has now been cleaned, but there was another fault code relating to the high pressure pump. But I don't want to spend that amount of money on it if the pump doesn't need replacing, does this sound like just a computer glitch or definitely a sign of impending fuel pump related doom? It's also strange how this started so soon after the MOT, when the engine has had very few issues in the past, and never just shut down like that, I'm worried that the dreaded emissions test revving won't have done it any favours.