The engine control relay is the main relay that is used to enable and disable power to the engine management components. The Elite 2500 has one dedicated engine control relay output (DPO 6 (Black/Red)) capable of sinking 1A Max current ( ie 5 x 80 Ohm relays wired in parallel). An Ignition input signal is required by the ECU for this function to operate correctly. When the ECU has a 12V ignition signal on pin A13, the ECR output is enabled (Pin A25) and the ECR relays will engage and power up the engine management components. Upon turning the ignition off, the ECU has the ability to hold on the ECR which is especially useful in turbo timer applications and can be setup when this function is enabled.