Actually its not a pump at all, oil pressure from the engine fills a spring loaded cavity, at engine shutdown half of the oil is released by a solenoid and the spring reinjects it back into the oiling system. When the key is turned back on, the other half of the pressurized oil is released by a solenoid and spring while you wait for your glow plugs to cycle. only one hot wire, on in the run position, and one ground. If the system fails all that happens is the systems function returns to stock. I think I will buy me one after the new turbo is installed. I still plan to idle like I should but want more insurance after a 40 thousand mile turbo (that I believe the body shop killed for me).