Subaru STi to HFS-3 wiring diagrams (2004-2013)

[Richard L]

You only set up the failsafe after you have run the system for a week or two.

First set up the failsafe window:
1. With the engine running
2. Put the intended jet on the screen.
3. Put the "prk" jumper link to "SYS" to activate the system manually.
4. Set the SC trimmer (on gauge) until the gauge displays 6 bars. Put the jumper back to the "prk" slot
5. Set the WL ten clicks from fully counter-clockwse
6.. Set the WH ten clicks from fully clockwse
7. Go for a drive and make sure the failsafe does not trip.
8. If it trips, advance the WL trimmer counter-clockwise a click or two.
9. If it doesn't trip, advance the WL trimmer clockwise a click or two until it does. Then un-advance it a chick of two, That is it.

Once this is done, don't alter the threshold or gain on the controller Let me know how you get on up to this point.

Brown and white wire: (wire it at the ECU)
10. Key off .......... brown/white wire goes open-circiut
11. Key on ......... brown/white wire goes close-circuit
12. During spray ..... brown/white stays close-circuit
13. Loss of spray ..... brown/white goes open-circuit

Wire the brown and white wire exactly as the diagram, cutting the "ground" side of the BCV. Brown goes to the BVC side and white goes to the ECU side.

If you don't want CEL after failsafe trigger, link the DR=1 jumper (PAGE 12.6 of the user manual)

[slick362]

High Richard,

I followed the instructions and can`t get the fail safe working. Soon as I wire it in like this I get CEL on and can`t build proper boost. I was on to Cam at light speed inovations where I bought the kit, and he couldn`t help and suggested I try you. Could it be something with the control unit itself?

Thanks