This is a page about the window controller as used in the later 928 models. It is  a clever design based on a microcontroller and some relays. Some functions like closing one window at the time, and automatically close all windows and sunroof are operated by the controller autonomously.

Window Control Unit 928 618 240 00 | 928 618 040 00

I had a problem where there was a delay in the operation of the windows and sunroof and identified this to the control box which has the number 928 618 040 00 in the PET and 928 618 240 00 on the box itself. I drive a 1990 S4 RHD.

I have swopped it for a replacement unit and have full function back and set to finding out the cause of the problem (see photo). It seems the one contact/switch has melted so was sticking. This part connects to the connection with the number "35".

Not knowing if the control box part has just failed or something like a high current to be at fault can anyone shed any light to which window / sunroof number "35" connects to and whether the faulty contact/switch in the control unit can be replaced - and if so what is such a part called.

35 is a common pin to all the motors (windows/sunroof) - that is reversible in polarity.

The replacement part is a relay - very much like a 53B std relay without a can but with PCB pin connections on the bottom. Look for PCB mount SPDT 12v coil relay rated at 20A+(DC). However you really need an exact match for a >25 year old part...

Alan `
Just for the record the original unit 928 618 240 00 has all the functionality as described. PET refers to part number 928 618 040 00.
The original part number 928 618 240 00 is not even recognized in the Porsche system.
928 618 040 00 does not have full functionality - windows and sunroof will open and close but the key turned to the right in the door and hatch WILL NOT close the open windows and sunroof.
One push up and down also does not work.
I have a PTech in Germany in an effort to push Porsche to resolve this anomaly
Made an offer for the VW Corrado unit (I know I am cheap).
New unit from Porsche 928 618 040 00 and once the label is removed 1L0 959 875A.
I will test fit this unit in the GTS as well as the VW Corrado unit and report back on functionality.
I did some research on the 1L0 959 875A and it seems to be used only in a Seat Toledo.
ps: Did not work reference posts above 8>( At least we tried.
Recently fitted 928 618 040 00 to replace failed 928 618 240 00 (same burned contact at 35 as original post) to my MY 93 GTS (Euro) and all works perfectly except auto close of windows & roof with key. For sake of clarity one touch up/down works fine.

Dublin, Ireland

Alain, thank you.
so the complete Mouser part number is 822E-1C? (1C = SPDT)
flux type is "better" than open? I am not even sure that flux type is?
also Mouser offers same parts but with high sensitivity; again, I do not know what this means, but the information is on the Mouser website data sheet if you can interpret.

I feel we are making progress.
I believe that I have indeed damaged my PCB; I did not have this issue before the disassembly.
The desired relay is either 822E-1C or 822EN-1C, with the difference being standard vs. high sensitivity. Can someone comment on whether one is "better" than the other? more responsive or efficient?

Window controller relay 822E-1C.pdf

Volkswagen Corrado, different functionality, same design



Window controller relay powerflow.pdf