Circuit Description

WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue. However, it is still accessible from the selected car via links, so may be relevant.

The HVAC control module commands right air temperature actuator movement with one of three voltage signals applied to the right air temperature door control circuit. A low voltage of zero volts moves the right air temperature door toward full hot. A voltage of 2.5 volts stops the actuator. A voltage of 5 volts moves the right air temperature door toward full cold. The HVAC control module determines the current position of the actuator by monitoring the feedback voltage of the right air temperature door position signal circuit. The feedback potentiometer position is a function of the actuator position. A high voltage indicates a full cold right air temperature door position. A low voltage indicates a full hot right air temperature door position. The HVAC control module controls the right air temperature door position in order to maintain the selected air temperature.

Whenever the HVAC control module keep alive memory battery power is interrupted, the HVAC control module will perform a recalibration of the actuators. During recalibration, the HVAC control module will drive the actuators to their minimum and maximum travel extremes. The HVAC control module will then calculate a travel range from this data and compare it to a calibrated range within the HVAC control module. If the actual travel range is not within the calibrated expected range, the actuator will be considered not calibrated and the DTC will set.