Yes the dealer will charge you oh $70 -$100 to reset it and you just buy VCDS and take control of the diagnostics on your car. My wife's car is a 2013 Golf and just like you I had changed the oil and it came on. So in VCDS Hex-Com there is a reset SRI screen where you can reset them.
You are using a generic reader as I do not find P0252 at the Ross tech wiki. Some people think this:
P0252 Injection pump metering control "A" range performance, possible causes Cam/ Rotor /Injector I see this alot,the service manual talks about cylinder 3 with the needle lift sensor to be...
16683/P0299/000665 - Boost Pressure Regulation: Control Range Not Reached
Reduced Power Output
Hoses/Pipes incorrect connected, disconnected or leaking
Charger Pressure Control defective
Diverter Valve faulty
This is what I found: So you just have to find out which EGT sensor is Bank 1 Sensor 3 Do you own VCDS?
009258 - Exhaust Gas Temperature Sensor; B1 S3
P242A - 000 - Malfunction - MIL ON
Fault Status: 11100000...