My Tahoe SSV fans would go on high for no reason whatsoever. Chevy sent me a recall for the fan system. Look yours up, it may be included in the recall. My boarder patrol teuck has an "enhanced cooling package" or "cooling package upgrade" with upgraded cooling fans among other things. Special heavy duty radiator cost me $700 for the part alone from Chevy(only place that had it)I fixed the fan issue myself with HPtuners. The fans have a low, medium, and high that have a few adjustments, such as RPM and coolant temp. My thought is it may not be an issue with the hardware but rather the software.