This is some info that I've come across.
The automatic climate control system (C6
uses the following five actuators in order to adjust the temperature and the air distribution:
* The electric actuator or the temperature actuator controls the temperature valve.
* The air inlet actuator controls the air inlet valve.
* The slave actuator controls the heater slave valve.
* The mode actuator controls the mode valve.
* The defroster actuator controls the defroster valve.
When servicing an actuator, replace parts with the 4 correct service parts for the actuator being serviced. The electric actuator for the automatic climate control system (C6
has a green R on the top in order to differentiate the electric actuator from the electric actuator used on the manual climate control systems (C42, C60).
The electric actuator contains a feedback potentiometer. The feedback potentiometer reports the position of the electric actuator to the Electronic Climate Control (ECC) module (Control Assembly). Do not test the electric actuator for movement while disconnected from the heater/vent module with the temperature **** on the control assembly. If the electric actuator is removed or replaced for service the actuator must be initialized. Refer to Temperature Actuator Replacement in Heating, Ventilation and Air Conditioning for the initialization procedure.
The air inlet actuator and the slave actuator are vacuum motors with one vacuum port in order to move the attached valves in one direction.
The mode actuator and the defroster actuator are vacuum motors with two vacuum ports in order to move the attached valves in two directions.
Re-Calibrating Actuators After Power Loss
Calibration of the Electronic Climate Control (ECC) module occurs whenever B+ is removed and then restored to the ECC module. During this calibration process the ECC module will automatically command the temperature door to the full HEAT position and then to full COLD position. The ECC module records both the minimum and maximum door positions and uses this data, which is in counts, to determine temperature door settings based on customer selected temperature settings.
IMPORTANT: Do not select or use the scan tool HVAC menu during the ECC module calibration period or the ECC module will not calibrate properly.
If the ECC module has been interrupted by scan tool operation the temperature door will become inoperative. If this should occur then:
1. Turn the ignition switch to the OFF position.
2. Disconnect the scan tool from the Data Link Connector (DLC) .
3. Remove the RDO BATT fuse for 10 seconds and then reinstall the fuse.
4. Place the ignition switch in the RUN position and wait 40 seconds for the ECC module to initialize.
This is at least the connector view of it. Haven't found a schematic. This information is not from the 90'* Bonneville, but I believe it to be at least similar.