TD5. Last week was first week was first time I saw this light come on for about 2 seconds. Drove 12 miles today and it came on again 3 times. Possible slight hesitancy in revs when it happens. Any ideas or how do I get it diagnosed?

I had a problem some years ago when I first bought my TD5 where the engine light would come on and it wouldn't rev.
It turned out to be deterioration in the wiring loom between the accelerator pedal and the ECU. The fact that yours is coming on occasionally suggests something like a poor connection. Mine was initially fixed by a garage who soldered some new wires in, and then a few years later I got a whole new red-plug wiring loom.

With intermittent faults it is often hard to diagnose them because the vehicle will no doubt behave impeccably in the presence of diagnostic equipment or a garage mechanic. If it's the feed from the accelerator pedal (or 'driver demand' as they call it) you might be able to see this via a fault code reader like a Nanocom or similar. In normal operation you can view the voltages going up and down as the pedal is pressed, but when the fault is present they won't move, for obvious reasons.

Ok Advised it may be sticking turbo actuator. Took Turbo heat shield off (Drilled out 4 rivets and undid 2 nuts) and uncoupled actuator lever off the "butterfly". Moved very freely. Re-assembled and Riveted cover back on. Next job took off rocker cover and changed injector loom, straightforward. Replaced rocker cover with new gasket. Noticed front camshaft oils seal and disc half out. Replaced with new one. Then found ecu under drivers seat, unbolted it and took out plugs (After disconnecting batter!). As many have warned, red plug full of oil (capillary action either from the injector loom end, but also possibly all the oil which was being blown out of cam oils seal). Stood ecu on end for 4 hours, then cleaned socket and red plug with aerosol brake cleaner, Put it all back together. Light work and market trip today with heavy load. No engine management light (so far) so hoping its sorted!

Good work. Hopefully you've fixed it.