So recently I have fallen foul of my lovely sigma alarm playing up ... long story short it was cutting power to my fuel pump meaning that on occasion it would prevent the car from starting and cause it to randomly cut out while driving. What I have done is wire in a new relay with an ignition pick up so that basically I'm bypassing the sigma in sending power to the fuel pump controller when ignition is on. I the car would then start and run fine but occasionally it would cut fuel supply when driving but it would still sometimes cut out. So I have purchase a second hand controller believing that this was the issue. However its still randomly cutting out whe driving which can be resolved by flicking the key on and off quickly and all is good once again. As a process of elimination I made some jumper wires to bypass the fuel pump controller. I ran the car like this and covered over 500 miles without issue. Only problem there is that the fuel pump is running at 100% duty at all times which is not ideal. Just wondering if anyone can offer up some suggestions as to where to look next as I don't want the pump running flat out as soon as i turn ignition on. Any help would be greatly appreciated as this is becoming a pain now!

 

Have established from previous threads/posts you have a MY01/02 WRX.
AFAIK prior to MY03 the Sigma alarm wiring was not incorporated into the OEM wiring looms, so is basically an add-on installed at time of import.
From MY03 according to the wiring diagrams the Sigma alarm only cuts the power to the starter motor via the blue security relay. Fuel pump cut out is down to the ECU's inbuilt immobilising circuits and the fuel pump controller.
Whether or not MY01/02 vehicles have the same alarm immobiliser setup I cannot say but according to the various model year engine wiring diagrams, they have very similar fuel pump relay/controller setups.