A4 - 2.5 TDI glow plug indicator flashing - HELP!

Hi All I was hoping you may be able to assist me with your combined knowledge. We have owned our 2.5 TDI Quattro since March with it running perfectly. I was driving it last weekend, when the glow plug indicator light flashed for about 20 seconds. There didnt seemt to be any change in the engine, or anything else to cause me concern so i continued the 20 miles home. On consulting the manual, it reads "if a fault should occur in the engine managment sytem while the car is moving, the indicator lamp will start flashing. The system will switch automatically to the fail safe mode and the engine power will be slightly reduced. Take the car to an Audi dealer without delay." I have just had a friend connect it to reader, and the only code it came up with related to the brakes - which appear to working fine ( im sure it was 00741). Im getting really concerned, but cant really afford to take the car to Audi dealer at present. I would appreciate any help or ideas.