Some error codes and throttle body Train/update 2.0 TDI CFFB

[Laher1992]

Hi, few days ago on a drive i had my glow plugs flash with a slight whirring noise which sounded like it came from the engine side and then going into limp mode. I parked up, ignition off and back on and the flashing glow plug light went off and the whirring noise remained for 20 minutes after and dissapeared since then. Recently, since then I had a diagnostic tool inserted and had the error codes 5211,5212,5231 p0087 - Fuel Rail system pressure too low - Open Circuit - Electrical Fault in Circuit - Can not be tested at this time. 3 Seperate errors. Took it to garage and he said first we will change the clogged fuel filter and take it from there. Now if it happens again, which it will because the exact same thing happened 3 months ago (I didnt get the fuel filter replaced then), The dealer said he will move on to the next steps as to identify the problem because the car ran fine. Anything know what else this could be or has anyone had this same issue with their CFFB VAG engine?
I also had another error code show up which was 5286 P0121 - Throttle position sensor (G69) : Implausible Signal - Short to plus. Anyone know what this "Short to plus" means? The ecu logged my flashing glow plug light issue as the first error regarding the fuel rail system, but this error also showed up so I might as well get that sorted too. I was looking at this throttle body sensor online and it said "Control unit/software must be trained/updated". Does this mean I would have to get the new sensor reprogrammed with a diagnostic tool or would just letting the ecu relearn the new valve and behaviours until it starts working properly? I was thinking of getting a new throttle body replacement and clear that error once I do hoping to not see this error again. I have no idea what the whirring noise was but if anyone can help in these issues that I am having it would be very much appreciated, Thanks.

[philipharmes]

You will probably find that the throttle valve, located on the inlet just behind the radiator, is full of conductive black engine oil.

The oil comes from the EGR just above & runs down along the throttle spindle into the valve electronics at the side.

If you are into DIY, remove the valve, then remove the plastic side cover which will probably be full of oil.

Look carefully at the plastic gears, if they are good & none broken & operating the flap properly then clean the unit thoroughly.
That includes removing the electric drive motor & washing it out with contact cleaner or brake cleaner.
Wash all the electronics out as well to get rid of the conductive oil.

If you aren't into DIY or the plastic gears are worn/ broken, get a new one fitted.

Get the codes cleared & go from there as there may be other problems as well.

Get this done ASAP as the engine won't do a DPF regen with this code present.

[Laher1992]

I have ordered a new throttle body unit and will be getting it fitted by the garage. Shall I tell him to clean out my valve at the same time or is this something thats included with my unit? Also i may suspect the wiring to the throttle body might be buggering up so how do i go about getting new wiring? Bosch VW throttle connector (link) will that work? Il be getting a throttle body and all it says it requires the D shape connector