Hi,
im after successfully finishing a small issue that I was having with my car. I wrote up a short guide to help anyone else in a similar situation. VCDS was throwing up an error for the engine. In the logs, it stated that two glow plugs were gone (see below).

Code:
Chassis Type: 8K (8T0)
Scan: 01 03 05 08 09 15 16 17 19 42 46 52 53 56 62 72

VIN: WAUZZZ8K1223456 Mileage: 212710km-132171miles

01-Engine -- Status: Malfunction 0010

.......


-------------------------------------------------------------------------------
Address 01: Engine (J623-CAGA)       Labels: 03L-906-022-CAG.clb
   Part No SW: 03L 906 022 B    HW: 03L 906 022 B
   Component: R4 2,0L EDC   H01 3210  
   Revision: --H01---    
   Coding: 0104002C18072018
   Shop #: WSC 06325 000 00000
   ASAM Dataset: EV_ECM20TDI03L906022B A01014
   ROD: EV_ECM20TDI03L906022B.rod
   VCID: 245FFA9B7EDB06A25B085A5-8070

2 Faults Found:
4984 - Cylinder 1 Glow Plug Circuit (Q10) 
          P0671 00 [101] - Electrical Fault
          Not Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 212624 km
                    Date: 2016.10.08
                    Time: 12:24:02

4987 - Cylinder 4 Glow Plug Circuit (Q13) 
          P0674 00 [101] - Electrical Fault
          Not Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 212624 km
                    Date: 2016.10.08
                    Time: 12:24:02
The glow plugs are only really needed to start the vehicle in colder weather. You can get away with just two working to start the engine, but i decided that it was better to get the error over and done with. To fix it, you will need two replacement glow plugs. My engine is a CAGA, and I bought two NGK Glow Plugs.

Remove the black cover from the engine. You can just pull it up by hand.


REmove the foam covering from the top;





Locate the glow plugs that you have to remove. You can match up the error code (Q10, Q12, etc) with their location using the image below.




Using a long nose pliers or the special pliers as shown above, pull up the rubber connector.




Once that is done, you will need a 10mm socket, long bodied, to remove the glow plug. I had no 1/4" wrench, so I made do with a large philips screwdriver and insulation tape, as shown below.



With a bit of elbow grease, the glow plug should come loose. Take care removing it as some are ceramic and can break. You dont want any part to be dropping into the cylinder.
Once you have it removed, you can check that it is a damaged one with a multimeter. Using a resistance test, the element on a working one will be around >5 ohm.


Follow the same process to put back in the new glow plug.

Using VCDS, you can then do a Autoscan, followed by a code clear to remove the errors.


I hope that helps!