"switching module"

[R501]

part number 22710 N4400

It sits under the driver side seat but I have no idea what it does.

[HS30-H]

22710-N4400 is part of the catalytic converter operating system on later production NAPS (Nissan Anti Pollution System-equipped) Japanese market models:

[R501]

That's fantastic, where can I access that english/JDM service manual you posted?

[HS30-H]

9 hours ago, R501 said:

That's fantastic, where can I access that english/JDM service manual you posted?

PM me your e-mail address and I'll see if I can send a PDF file to you.

[dutchzcarguy]

i thought you look under resources and downloads on this site! You see lots of service manuals under resources on the main site!

Classic Zcar Club File Downloads (classiczcars.com)

[R501]

Understood, but I didn't see a JDM S31 parts resource.   HS30-H hooked me up!

[dutchzcarguy]

Maybe now you can put that on there, send a copy to @Mike (JDM S31 parts resource)

[HS30-H]

3 hours ago, dutchzcarguy said:

Maybe now you can put that on there, send a copy to @Mike (JDM S31 parts resource)

There's a public distribution restriction on it.