Throttle Body and Heated WW nozzels
A little late to the party here but thought I'd post what issues I've had with my 2009 GTi (TSI) Dsg. Current mileage is 85,862 miles
I bought the car as a 2nd owner about 5 years ago with 46K mile. Original owner was meticulous with maintenance (all his records came with the car). Right before he traded it he had the intake manifold replaced under warranty for the flapper valve motor failure.
I drove the car for 5 years changing the oil and filter at 5K mile intervals. Previous owner installed a Carbino intake so I cleaned and oiled the cotton filter twice a year. (2) DSG services one at 40K by the previous owner and one at 80K by me.
I had the fuel filter replaced shortly after I purchased the car. At 75K miles I replaced the original spark plugs and all 4 coil packs as well as the PCV unit.
At just about 61K miles I was having random starting issues to the point of the car leaving me stranded several times. 1st time I took it in they found no problem. I pulled my own VCDS codes and provided them, but they couldn't get the car to repeat the issue while they had it.
I was a bit frustrated at that time because now I had to wait for it to happen again. And it did within a week. Pulled the codes again, same issue, same fault codes. Had it towed back to the dealer and still couldn't get it to repeat the issue. This time they diagnosed by the fault codes that I was having a throttle body issue. Bear in mind each time I'm being charged a diagnostic fee.
I then made them aware of the TSB for the throttle body wiring harness. On some TSI engines the wiring harness to the TB is manufactured too short. Over time the rocking and movement of the engine stresses the wires and they can break, or in my case partially break, causing intermittent running issues.
Then they try to tell me this isn't covered under the 5yr/60K mileage drive train warranty. So I go back and forth with VWOA and they agree to cover everything except my initial diagnostic fee of $125. It took a tech almost the entire day to cut, splice and extend each individual wire in the harness. Normally about an $750 repair.
So be aware if you have issues it could be your throttle body wiring harness.
The only other issue I've had is last year I abruptly lost, A/C, Hill Hold Assist, heated seats and some other random electrical thing. Dealer took two days to track down a broken wire in the harness that runs to the heated windshield washer nozzles. They charged me less than they had in diagnostic hours for sure. I think the repair was less than $300. Trouble shooting electrical is a biatch.
I just bought a 2017 GTi Sport, but I'm keeping the 2009 GTi TSI for the gf to drive.