HFS4 install with Unichip question

[icarus]

the fail safe on the hfs; 'the orange is factory configured to send out a voltage of 4.7V DC under a ?no fault ? condition, from idle to full boost.'

Is the no fault signal sent when the hfs is active or only when it is injecting water? I'd like to use it to switch on a MAP on the unichip that would advance the timing when using 87 octane but only if the signal is sent when injecting water.