Automatic Operation

In automatic operation, the HVAC control module will maintain the comfort level inside of the vehicle by controlling the air conditioning (A/C) compressor clutch, the blower motor, the air temperature actuators, mode actuator and recirculation.

To place the HVAC system in automatic mode, the following is required:

• The blower motor switch must be in the AUTO position.
• The air temperature switch must be in any other position other than 60 or 90 degrees.
• The mode switch must be in the AUTO position.

Once the desired temperature is reached, the blower motor, mode, recirculation and temperature actuators will automatically adjust to maintain the temperature selected, except in the extreme temperature positions. The HVAC control module performs the following functions to maintain the desired air temperature:

• Regulate blower motor speed
• Position the air temperature actuator
• Position the mode actuator
• Position the recirculation actuator

When the warmest position is selected in automatic operation the blower speed, based on coolant temperature, will increase gradually until the vehicle reaches normal operating temperature. When normal operating temperature is reached the blower will stay on high speed and the air temperature actuators will stay in the full heat position. When the coldest position is selected in automatic operation the blower will stay on high and the air temperature actuators will stay in the full cold position.

In cold temperatures, the automatic HVAC system will provide heat in the most efficient manner. The vehicle operator can select an extreme temperature setting but the system will not warm the vehicle any faster. In warm temperatures, the automatic HVAC system will also provide air conditioning in the most efficient manner. Selecting an extreme cool temperature will not cool the vehicle any faster.