Part number for heater support pump pls

[NC35]

Hi Everyone,
Bit of help pls.
I have a P16C700 - heater support pump "locked" error code.
Just wondering what part number to order... VW are not being very helpful, all I know it starts with 5Q0 & costs about £175 + vat.
Similar pumps for the Audi VW range starting with the same part number are about £40 delivered online.
Any help or advice please. From what I have read there are 3 x Aux Pumps, going to be trial and error to find the faulty one!!!
VIN WV1ZZZ7HZHH038114
2017 CXHA 150HP 2.0 TDi
Any help with the part number or the pump location appreciated.
TIA

 

[bluezie]

Try disconnecting the wiring to each pump in turn, then observe the fault codes. From these you should be able to deduce which pump is faulty. I suppose it all depends on how good your code reader is though, some only give basic generic information.