Monitoring Solid State OEM ECU Grounds

[alexmas0n]

Hi guys,

I am very new to using a PDM and am wiring my fuel pump. My current ECU grounds a pin which normally activates a fuel pump relay. This relay is gone and the pump is now fed by the PDM. Except, I would like to have the PDM monitor this ECU pin and activate the fuel pump circuit whenever the ECU grounds this pin. Any ideas?

Thanks

[tepid1]

Wire it into the digital input on the PDM.

[the_bluester]

Exactly what tepid1 said. Wire the ECU control output to a digital input pin on the PDM and use the input pin to control the fuel pump output. You could also add a condition that your main ignition power has to be on as well to ensure that an ECU fault would not result in the fuel pump running if the ignition was off.