Dual Zone Control Switch

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

The passenger air temperature switch is provided to allow the passenger to set air discharge temperatures on the passenger side of the vehicle. Passenger temperatures can be set from 15-32°C (60-90°F). To activate the dual zone, the passenger air temperature switch to the desired offset. If the passenger air temperature switch has been turned on, it can be turned off by pressing the passenger switch. Greater sunload on one side of the vehicle may cause the discharge air temperatures to be different, even when the HVAC system is not operating in a dual zone mode.

The HVAC control module provides power and ground to the passenger air temperature actuator. The HVAC control module receives power from the under hood electrical center through the ignition 3 voltage circuit. Ground is provided by the ground circuit.

The passenger air temperature actuator is a reverse polarity motor. Each circuit provides both power and ground to the passenger air temperature actuator. When the passenger air temperature actuator is being held in position, both of the passenger air temperature door control circuits have 12 volts applied to both sides of the actuator motor. This holds the actuator stationary. When a temperature offset is requested, one of the passenger air temperature door control circuits will ground, driving the passenger air temperature actuator into the desired temperature offset.