Given all these faulty thermostat readings, I decided to check mine and of course it was faulty. I had planned on changing this when my work schedule got a bit quieter. Interestingly, I called BMW Seattle today to book my X5 in to get the faulty DeNox reading fixed (hopefully under CA emissions) and to my surprise the lady on the phone said my vehicle had an open recall on a faulty thermostat. Mine is a 2012 X5d. Maybe some of you have the same open recall. I was very relieved to say the least.