Aux 6 giving ground when off

[Rod635csi]

I have installed twin inline aem “044” pumps that I want to run staged, my lift pump and main inline fuel pump work properly, but it seems the secondary 044 pump relay is getting ground from aux 6 on g4+ monsoon fuel pump is staying on with the key on , ecu is giving ground to relay even when off. Is there a way to fix this through software? The relay for second pump shares all the same supply as the other two pump relays except for its ground (aux 6) if I disconnect the ground wire coming from aux 6 on ecu The secondary pump stops running. I would like to set it up to come on based on boost and ethanol content. Im curious Is it possible to have it cycle with the other two pumps with key on to prevent it seizing but not run with them all the time? I have aux 6 set to “off”  Any help or suggestions are much appreciated. Thanks 

[DerekAE86]

This is expected behaviour. The AUX outputs will be ground when the ECU is off.

You should always supply the power to the relay coil from an ignition switched source.

[Rod635csi]

I was confident I had it right but, I went back and verified the wiring to secondary pump relay and sure enough I had a constant 12v wired to pin 86 the issue has been corrected. Thank you. Do you have any suggestions on how I can have secondary pump cycle with key on engine off the way the main pump does but only turn on when engine is running based on map/ethanol  content? Am I only limited to 2 conditions?

[DerekAE86]

You could create a GP Output with the conditions to only activate if the map is reading over 110kpa and the eth content is over 50% for example.

And then create a Virtual Aux that will go high if the RPM is less than 1 and Engine Running Time is less than 1s and use that as the trigger for a Timer.

Then use the Timer to also trigger the fuel pump for 2seconds:

There might be a more elegant way of doing it - I don't know a huge amount about the G4+ platform.

Edit: Thinking about it now, the "Reset when Off" will probably throw a spanner in the works for the above example.
Brain isn't working hard enough yet. Need more coffee.

[Rod635csi]

Thank you, your reply is much appreciated.

[DerekAE86]

9 hours ago, Rod635csi said:

Thank you, your reply is much appreciated.

I'm not actually confident the above example will work correctly. But it should give you an idea of how you might be able to achieve the results.

Could definitely do it with the use of an additional Virtual Aux but it'll start to get cumbersome.
Probably need someone with more knowledge on the logic functions in the G4+ as it seems a little more limited than the G4x.

Edit: So here is another possible way of doing it which should work;

This will turn on the 2nd pump at over 110kPa MAP (so when you start making boost)
Or it will be on all the time if you have more than 50% Ethanol content in the fuel.
Or it will prime for 2s when RPM is at 0.

The reason you'd need a 2nd Virtual Aux is because "Reset when Off" will hold the Timer at 0s which means whenever the "Prime" Virtual Aux is inactive the Timer will always be 0s causing the pump to always be on under the previous example.
Having the 2nd Virtual Aux allows for the extra logic to only activate if the Timer is more than 0.1s but less than 2s.
That way it the Timer actually has to actually start counting up.

However I'm not actually sure if the "Engine Running Time" resets to 0s immediately when RPM drops to 0, or it holds at the max runtime until power cycle or engine restart. If it does drop to 0s straight away it would cause the 2nd pump to prime for 2s when you stall the engine.

Probably not a huge issue?

[Rod635csi]

I don’t see it being an issue I’ll try it out, Man thanks again I plugged in your first example except I changed 2sec to 5sec and it worked perfectly as elegant as can be 2nd pump primes with main pump I can confirm by watching fuel pressure with main pump only I get 332kpa during prime and with both pumps I get 340kpa during prime, I’ll try out 2nd example but haven’t had any issues with pump 2 staying running but I haven’t fired the car up since installing only key on engine off waiting for a radiator