This being[2018 CC Extended cab I4 6 speed manual] my first 'Modern Truck', [My last truck was a 1982 Datsun Diesel], I have never had a external temp monitor. The other day, I pulled out of my garage, and headed to the store. The temp was showing 63degF and after 20 mins it never changed, but it was 80+degF outside! When I got home , I inspected the sensor and a large bug had covered about 1/2 of the sensor. Got a small brush and after I,cleaned it works fine now.