Hi @hammrind
So from the information available for the WisGate and compute modules. It looks like the compute module 5 has only 1 PCIe output. This is connected to a 1 - 4 PCIe expander on the WisGate Connect which provides PCIe to the expansion slots.
With the expansion slot in the way, even if you could remap the compute module 5 pcie to SDIO, I would advise against this as it is the root of the PCIe tree and will impact the other expansion slots. I can’t determine if such a remap of pins is possible.
I’m not seeing SDIO on slot 3, just PCIe, USB, I2C, and SIM.
Whether or not the pins these interfaces are routed too have an SDIO alternative function is, unfortunately, irrelevant. I’ve found a pinout from the manufacturer of your converter board here: http://ableconn.com/upload/MPEX-M2WL-00BM.2pinout.pdf
It looks like the SDIO lines aren’t broken out from the M.2 E connector to the PCIe pins. So that won’t work.
If you must use the mini PCIe slot, you may want to look at using something like Seeed Studio’s WIO-WM6180, in SPI mode, in mPCIe slot 2. This won’t be able to use Wi-Fi powersave features though, as pin 31 of the mPCIe slot 2 connector isn’t connected on the WisGate.
To use SDIO, it looks like you will need to use the 40p Raspberry Pi header if it is available.
Probably not the answer you were hoping for. Please let me know if I need to clarify anything further or can help in any other way!