Volvo Forums - Volvo Enthusiasts Forum - ECT/Fan running all the time issue

Hello everyone,

I am currently having an issue with my 2002 Volvo S60 2.4L Turbo AWD. When I bought the car I noticed that the cooling fans seemed to run continuously shortly after the engine was started but the car seemed to run well. I figured that this was a small issue and I got the car for cheap because the person thought it needed a rack and pinion when it actually didn't. So now I have been chasing this fan running all the time issue for a few months now and can't seem to get anywhere. It has a "2000" code after running for ~30 seconds which according to my scan tool means coolant temp sensor circuit high but according to Mitchell on demand it means coolant temp sensor faulty signal. So far I have changed the sensor twice, ran brand new wires that were the same gauge as the old all the way from the sensor to the PCM, changed the cooling fan and module assembly, and thermostat and housing. At this point all I can think of if the PCM being the issue as I have changed every other part of the circuit. I have verified with my scan tool that the sensor reads good for a short period of time then goes to 300+deg F, I cannot read the actual sensor voltage with my scan tool unfortunately so I cannot tell if this is an inferred number or the circuit actually goes open, I plan to get a pyrometer and my meter on it in the next few days to do more diagnostics. The system seems to be building pressure and the coolant seems okay, I am able to command the PWM fans on with my scan tool and they respond when commanded to different percentages. I am not sure what else it could be at this point, does anyone know if this is a common issue or if there is any way to truly verify that it is a PCM issue before I take it to a dealer and have a new PCM put in it? Thank you in advance for any feedback!