So I’ve got the following error on Cisco UCS IOmodule it came out of nowhere.

left IOM 4/1 (A) POST failure
Code: F0481

So the fix could be very simple try reseating or resetting the IOmodule that is giving the problem.
Before you attempt to do that make sure that you the other IOmodule in the Chassis is working fine and all the blades in the chassis have other path available when the IOmodule is reseated. If you have only one IOmodule then you would need to power down the blades first.

Here I’ll show how to reset IOmodule from UCSM.

First select the IOmodule that is giving problems and click Reset IO Module

You’ll be prompted to confirm

You should see now that IOmodule is not reachable and one path for Chassis is down.
Also Critical errors and Warnings will be logged.

Wait for the IOmodule to comeback and the errors to clear.

If all is clear then monitor this module for couple weeks or so. If the same Error appears on IOmodule then call Cisco support to get the module replaced. I’ve seen where the error would reappear after 2-7 days. In that case call Cisco support to get IOmodule replaced.