Glow plug defect

[bmassaer]

In our 2007 Cali, I have this warning light coming up. The mechanic told me one of the glow plugs is not working anymore. But he assured me this would cause no problem (unless it would freeze under -5°C) and the fix takes a lot of time. Can I trust this? And if so, is it possible to adjust the software so that the warning light does not repeatedly come up for this problem?