Renault Trafic will not start?

My 1.9 traffic will not start, I have found that the fuel pressure sensor to not only have a 5 volt supply but it has 5 volts on the signal wire when it is disconnected from the sensor, I have checked the wire at the ECU and it has the 5 volt there also. I did clean a blue multi plug in the fuse box under the bonnet and it cleared the fault and it started, went back in a few days and the fault was still there. tried what I had done previously but no luck. any ideas please?