code diagnosis help.


New member
Apr 7, 2021
I have a 2005 Golf 2.0 TDI, automatic gearbox, UK spec. I originally received a P0727 fault code, with a check engine light and an emission workshop warning when I turned on my vehicle. Within 3 days, the glow plug light started flashing and I pulled P2102 and P2100 fault code. if I turn my car off for eight or so hours, the low plug light stops flashing. Within 15 mins of driving it returns and the car decelerates, but continues to run tow I have to give it more pedal. It is also difficult to start with the low plug light glowing and the associated P2102 and P2100 codes. When I searched the P0727 it directs me towards sensors, wiring, and possibly ECM or TCM. The P2100 or P2102 codes lead me toward a throttle valve/manifold flap. Is is possible the latter codes are causing the first or vice versa? Any advice would be greatly appreciated.

Johnny P

Jan 12, 2019
New Zealand
In my experience, the best thing to do is to address the first fault first. Then re-scan. Often the other ECM's are symptoms rather than errors.
Good luck.