How to read engine trouble codes.

[bruno666]

I was driving on the highway when my glow plug light started flashing.
I slowed down and drove in at the next gas station. I turned off the engine and looked if there were no visible defects. It was apparently not so I started the engine again and the light was gone. How can I find out which error code it was?
The car is a 2,0 diesel (rf2 engine). I have a list of trouble codes but not at guide to recall them.

 

[Ward83]

Most auto parts stores should be able to read them for you. To do it yourself, you need an OBD2 code scanner, like this: https://www.amazon.com (commissions earned)