A method includes receiving, at a first processing device of an input/output module (IOM), new firmware data for the IOM. The method also includes sending an output hold command from the first processing device to a second processing device of the IOM. The method further includes upgrading firmware of the IOM with the new firmware data using the first processing device and attempting a reboot of the first processing device. In addition, the method includes, in response to the output hold command and during the upgrading of the firmware and the rebooting of the first processing device, using the second processing device to cause a field circuit of the IOM to hold at least one previous output signal for one or more external devices.