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.

[Richard L]

The 5v appears as soon as the system is switched on when the dash gauge is on. It stays at 5V at "all time" until there is a faulty detected after the system is triggered.

If you wish to switch over to a new map when there is water flow, it is better to use the "water flow signal" output on the yellow wire of the green harness.

This wire has the following signal level:

1. No flow at idle: 0.5V
2. Flowing: 0.5V to 4.5V
3. Sensor fault: >4.6V

This is by far the most secure failsafe for your Unichip interface especially if you can use 1 & 3 as early warning.

[icarus]

Would I be correct in assuming the 0.5v to 4.5v is proportional to the flow rate or volume being injected?

[Richard L]

Yes. Make sure you select the correct flow table.

[icarus]

Ok, thank you very much for the info & prompt replies.