I have been having a hot start issue for a while now so i managed to borrow a diagnostic tool from a friend of mine who works at a garage.

After letting the car get to running temp the engine coolant temperature sensor read out changed from 86 dergrees celsius to minus 180 degrees celcius.

I have checked the resistance of the ECT sensor in hot water (above the temp that the problem is at) and the resistance read is correct

I have also checked the wiring from the sensor to the pcm and have no fault

The pcm has also been sent away and no fault found.

Has anyone ever had this problem or got any ideas?

 

What is the maximum temp the "diagnostic tool" can return?