Isn't that for the rear heat and A/C?
This is out of the OM:
To operate the rear air conditioning system, the front air conditioning system must be on. With the front air conditioning system off, the rear system controls can only be used to circulate air in the rear of the vehicle. To adjust the airflow speed, turn the fan knob (driver override switch), located on the floor console to 1, 2 or 3. The rear mode and temperature position will now mimic the front control system mode and passenger side temperature. To activate the second row seat controls in the following systems, set the fan knob, located on the front console, to R.
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