Quick question.
Can a virtual output be triggered by a switch to overide fucntions such as coolant fan & fuel pump?
Many thanks
YES but no whit virtual output, you need 2 relay
one relay for shortcut fuelpump and other for FAN , you make 2 parametric output and set the logical work for the condition of you need to shortcut the fan and pump .
you can shortcut the aux to the original relays whit the parametric relays or shortcut the power lines .
its only put a 5pin relay in the midle of the line
Example :
ECU AUX1 —(parametric output reay 30/87a)-- FAN Relay
ECU AUX2 (parametric output)----- 
in the 5 pin relay pin 30 and 87a its normaly conected , if you activated the relay pin 30 an 87a its on shortcut and the line its brake .
in the folowing example : if the metanol content its low of 70% turn off the fuel pump.
y
you can use this configuration for shut down the main relay and off everithing.
Sorry for my bad english am from chile 
i speak spanish native.