gk1

I have had my 2014 SQ5 for a couple years now and it has always started like a champ even in the coldest temperatures. But recently I found it to sound like it was struggling a bit to start in the cold. Figuring maybe a battery issue I had checked and tested it and even overnight conditioned it on a battery tender plus. Still the same...on days when temps warmed up it started fine but when cold (40F and below) it seemed off. Then I noticed over the past couple weeks that the ambient air temp reading was consistently 12 degrees too high. So even though it was 40F the other day the reading on the DIS says 52F. Replaced the ambient air temperature sensor and now it seems like the cold temperature start is back to normal. Anyone experience anything similar? I had thought the ambient air temp was just for DIS display and had nothing to do with the function of the engine, but it looks like it might. I just always figure the intake air temp sensor would take priority over ambient air temp sensor....weird, but glad it seems to work better now.

ex-quattro PETE

The ambient temp sensor on our 2015 q5 was behaving similarly to yours, reading at least 10 degrees high, but I did not notice any impact on cold starting.

However, the HVAC system does take the ambient temp reading into account to determine the difference between outside and inside and control how hard it needs to blow.