295 walpro help

curtisgjr

Lurker
Mar 27, 2020
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hey I was wondering if anyone knows what the signal coming out of EKPM3 . I mean does it send a 12v signal or does it change volts??
I was going to run this kit from battery and run the positive signal from ekpm3 to the blue trigger 12v lift fuel pump wire in theory to give full load without putting strain on ekpm3
any thoughts or suggestions for that..
I like the bm4 but 750.00 with oem hookup is more than I wanted to spend right now..
I should say 2007 335xi with upgraded to ekpm3 already was running walpro 450 saw this and figured I would give it a try..
first without the check valve and see if starts ok or if long starts I have highflow check valve if needed thanks for feedback I am on e..post and have not seen much info on this


Wiring_Diagram-Single.png
 

doublespaces

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Oct 18, 2016
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The ekp takes in can bus packets from the DME which carry a duty cycle it wants and the ekp turns that into PWM signal to the pump which you probably already know.

It's a signal that is switched on and off Basically, it is constantly activating and deactivating the power and that is how it controls speed of the pump, it switches from 12v on and off really fast. So if the DME asks for 50% duty cycle the ekp sends 12v to the pump half the time and nothing the other half. It might not be nothing but a much lower voltage.

Assuming there's a pull down voltage that can keep the relay open then you should be able to achieve your goal. If not, then I can't be sure exactly what results you'll get, I doubt it can remotely keep up with the pwm frequency, so it may just be stuck on anyway.

Moving this to the N54 section
 

doublespaces

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Oct 18, 2016
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Also if you want a battery terminal that goes off with the other electronics there is the flapper valve in the trunk. It gets 4.5-12v constantly from the moment you unlock the car until a few minutes afterward. Not as idea but it's a constant power rather than pwm.
 
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curtisgjr

Lurker
Mar 27, 2020
18
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I found a post with someone running a 295 on stock ekp3..
Thanks for helping out much appreciated