trabots

I have searched and searched however cannot find an answer to this. The Pierburg pump cannot be started without a signal from the ECU. I want my pump to turn on when the ignition is at position 2 without the engine running. I had an auto electrician connect it up in that manner. The pump would not start until the job was undone by re-connecting the power to the ECU source. The pump has had the required resistor put on the signal wire and has worked fine with ECU. How does that signal work and how can I get the pump to run with the engine off? Cheers.