ECT 2
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2015 Jaguar XKR-S, 2015 Jaguar XKR, 2014 Jaguar XKR-S, 2014 Jaguar XKR, and 2013 Jaguar XKR-S. However, it is still accessible from the selected car via links, so may be relevant.
ECT 2 is installed in the lower hose connector which attaches to the bottom of the thermostat. The input from this sensor is used for OBD (onboard diagnostic) 2 diagnostics and, in conjunction with the input from ECT 1, to confirm that the thermostat is functional.