Volkswagen Repair: engine light, enzo enzo, plug fuse

Question
I have a 2001 Jetta tdi, my check engine light comes on solid and my glow plug light flashes at the same time. I had it in to the dealer 3 times now and they cleaned out the carbon, reset the throttle sensor. When I leave the dealership the light is out but later in the evening it comes back on. Is there anything that you can suggest?
Thanks for any help you can give me.
Enzo

Answer
Enzo,

They cleaned out the carbon... I hope they checked the EGR valve, and air filter too.  Check and see if your glow plugs are OK.  Have they ever been changed? They should by now, and replace the glow plug fuse as well.  How old is your fuel filter?  Have it changed when you do the glow plugs.

Try these and good luck,

Paul