Code 15, AGAIN, Help

[pando666]

Well, got code 15(high voltage coolant temp sensor) 12 months back or so, replaced water temp sensor still got code 15, approx every month or so. Installed temporary wiring loom from sensor to ecu, still got code 15 ever month or so.So I installed a 2nd hand ECU, didnt get any codes for ages (thought all was good I FOUND THE PROBLEM HOORAH). But today F...ken bingo the light came on again I checked the code and here it is again CODE 15.
Has anyone got any ideas this one is killin me.
Cheers

[Not_An_Abba_Fan]

Did you replace the sensor or the sender? Two different things. It could be just a connection issue too, clean all connections to the ECU and make sure they are all tight.

[pando666]

definitly sensor not sender, sender goes to gauge, sensor goes to ECU

[pando666]

What do you mean by tight connections

[The1]

there should be 5 volts measuring on the 2 pins with the ignition on, sounds like either ecu again or there is a short. You say you wired a new wire back to the ecu, what about was that both? Maybe the other wire presuming earth isn't good.

[pando666]

I did do both wires back to approx 50mm from ecu connector.