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I am having issues with my Greddy Profec B Spec II, the EBC unit powers up, solenoid works, however, the EBC unit doesn't adjust voltage to the solenoid to govern its correct operation. Currently, the EBC unit supplies the solenoid with 12V, but once the desired boost level is reached, there is no change to the 12V to the solenoid to tell it to close.

Upon opening the EBC unit, I found that I am missing the Voltage Regulator (VR3, in the location circled below).

My EBC Unit with the missing VR3:

11vr3.jpg12vr3.jpg

Another EBC Unit with the VR3:

profecbs2vr3.jpg

Does anyone know the specs of the missing Voltage Regulator?

And, does anyone else have anymore insight into how the EBC Unit operates electronically to fix my issue?

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https://www.sau.com.au/forums/topic/380540-greddy-profec-b-spec-ii-problem/
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firstly, I am pretty sure the unit pulses the negative not the power to activate the solenoid. make sure there is no break in the wires from unit to the solenoid, they are very small and easily pinched if you don't route them properly. If you can run it on a dyno back probe the earth when target boost is reached and you should see it pulsing

The vr3 thingy is ulikely to be an issue unless the unit never worked, probably just a change in manufacturing over time.

personally i ditched my profec bs because I got sick of them failing in hard use (race/rally), I run the turbosmart now, similar unit but much better made.

I have checked the wiring to the solenoid, that is all in perfect working order.

I brought this second hand whilst I was in the states, so its history I don't know and it has never worked for me.

The VR3 position looks like it has had a Voltage Regulator there before, the underside of the PCB looks like it is still part of the rest of the circuit, it is just missing the Voltage Regulator.

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