Automatic Modes

The automatic HVAC system will warm up/cool down and maintain the interior temperature of the vehicle by controlling the A/C compressor clutch, blower motor, air temperature, mode and recirculation actuators to achieve the desired temperature. For fully automatic operation, both the blower and mode switches must be in the AUTO position. Blower speeds will change automatically based on inputs to the HVAC control module. The HVAC control module will always come back to the last settings after an ignition cycle.

In cold temperatures, the automatic HVAC system will provide heat in the most efficient manner. When the ambient air temperature is below 2°C (35°F) and engine coolant is below 10°C (50°F), the HVAC control mode will go into a purge mode. The HVAC control module will into a 60-second purge to the front defrost outlets. To warm the interior quickly, maximum heat mode is used where the blower is at maximum speed, floor mode, air temperature is in full hot and outside air is being drawn in.

The vehicle operator can select the extreme warm setting, but the system will not warm the vehicle any faster. Once the desired temperature is reached, the blower motor, mode, recirculation and temperature will be adjusted automatically by the HVAC control module. In warm temperatures, the automatic HVAC system will provide A/C in the most efficient manner. To cool the interior quickly, maximum cool mode is used where the blower is maximum speed, air temperature actuator is in full cold and the recirculation actuator is drawing air from inside the vehicle. The vehicle operator can select the extreme cool setting, but the system will not cool the vehicle any faster. Once the desired temperature is reached, the blower motor, mode, recirculation and temperature will be adjusted automatically by the HVAC control module.