Owners manual, page 224 up, lots of reasons for it to not function and climate control settings the require the engine running (AC Compressor) disable it. Can’t have AC working if engine is off.
Auto Stops may not occur and/or
Auto Starts may occur because:
. The climate control settings
require the engine to be running
to cool or heat the vehicle
interior.
. The vehicle battery charge
is low.
. The vehicle battery has recently
been disconnected.
. Minimum vehicle speed has not
been reached since the last
Auto Stop.
. The accelerator pedal is
pressed.
. The engine or transmission is
not at the required operating
temperature.
. The outside temperature is not
in the required operating range.
. The vehicle is in any gear other
than D (Drive).
. Tow/Haul Mode or other driver
modes have been selected.
. The vehicle is on a steep hill or
grade.
. The driver door has been
opened or the driver seat belt
has been unbuckled.
. The hood has been opened.
. The Auto Stop has reached the
maximum allowed time.