I am sure you must have some OBDII codes stored in your ECU!
Your 2002 CRD should have the lift pump installed as standard....check with tonycrd here on this forum>
Please try and extract some codes and then we should be able to help!
I had several electrical problems on my 2002 CRD which would cause the engine to die...pulled over to the side and re-start OK.
In my case what actually caused the failure was not speed related but a case of either:
1: Turning on the front wipers....even momentarily.
2: Turning on the aircon....even momentarily.
3: A cheap Italian performance box that I had plugged onto the fuel rail...to fool the ECU about fuel rail pressure, suddenly gave up the ghost with a "POP"

. I removed this cheap box and threw it away but the point is that something like a failing fuel rail sensor can cause you to grind to a halt....here an OBDII code should help!
The first two problems caused the alternator to up the charge on the battery to around 17 volts...the ECU picked up the overvoltage and powered the whole lot down!
I think you may have something similar whereby the ECU is picking up some problem and shutting down all systems....that is why you need to extract some error codes.
If you have a voltmeter, plug it into your cigar lighter up front and keep an eye on it as you speed up...I am interested to know if there is any sudden surge in voltage just before your engine dies!