Intermittent Temperature Sensor Faults, possible SMC issue?

Hi All,

I previously Possible faulty cpu temperature sensor spikes but no errors from ASD resulting in kernal_task spikes. I thought I had potentially remedied the problem by replacing the HDD data cable as I was getting bad read/write speeds but the issues seems to have comeback.

Running EFI ASD I get three sensor errors:

TC0D - SMC IO Failed

TC0P - SMC IO Failed

TM0P - SMC IO Failed

Which relates to the CPU 0 Die Analog, CPU Proximity and Battery Charger Proximity (which I think the last is the same as the 5/3.3V proximity) respectively.

This is backed up by abnormal readings in TGPro and iStats menu - readings over 100 and non-existent intermittently, and for prolonged periods of time - in a seemingly non-deterministic way - whilst all the other temperature sensors give normal readings.

Looking at the schematic for my logic board I think that it could potentially relate to U5510 “CPU Proximity/CPU Die/5V-3.3V Proximity “.

One last note is that my machine seems to have SMC Version (system): 1.68f99, which looking on apples website is for a new machine (but have read online that the european models may have this slightly newer version) just wanted to check if thats ok.

Any suggestions?