Idiot light

[MTNHDWR]

I have a 2000 D2. I understand that the idiot light that looks like a tiny green gear with an "s" in the middle is sport mode, but what is the tiny green gear with the "m" in the middle?
The reason I ask:
On ocasion I start my vehicle and both sport mode icon flash and the mysterious "m" light flash together. They remain flashing until I shut off the truck and restart. Can anyone help explain the light and why they may be flashing?

Thanks in advance.

 

[Puppy]

The M is for Manual mode, which according the owner's manual gives you complete control of gear selection when the T-Case is in low gear. It is engaged by pushing the"mode" button on the gear shift when in Low.

 

[andrewv]

It's a transmission code that points to the ECM, but I'd ignore it.

 

[MTNHDWR]

I recently flushed and changed my transmission fluid. Could this code be telling me something I should know about?