General Information

When the mode switch is toggled, a signal is sent from the HVAC control module (IPM) to the mode actuator through the mode door control circuit. When the mode actuator receives the signal, the mode actuator moves into the desired position.

The rear fuse block provides power to the mode actuator through the ignition 3 voltage circuit. Ground is provided by the low reference circuit, the IPM and ground circuit. Power and ground are provided to the IPM by the underhood fuse block on the battery positive and ground circuit.

The mode actuator is an electronic stepper motor with feedback potentiometers. Zero volts drives the actuator in one direction while 5 volts moves the actuator in the opposite direction. When the actuator receives 2.5 volts, actuator rotation stops. A 5-volt reference signal is sent out over the 5 volt reference circuit, from the IPM, to the mode actuator. When a desired mode setting is selected, whether manual or automatic, the logic circuit is used to determine the mode door position signals value. A separate 5 volt reference is sent from the IPM to the logic circuit. The IPM software uses this reference voltage to determine the mode actuators position through the mode position signal circuit. The motor moves the mode door to the desired position. Ground for the mode actuator are provided by the low reference circuit and IPM. Toggling the mode switch manually also activates the VF display for the mode selected.