On mine which is Volvo electrics as soon as you plug the 13 pin plug the ATC is activated and the little green/ red light on the A frame comes on.
Assuming that this is powered by pin 9 then the answer to your question is yes.
If I attach the caravan at night for an early start or over night on a ferry I will disconnect the plug just in case the battery is drained.
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XC60 2013 D5 215 SE Lux Nav geartronic
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