Cabin Heating

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

Engine coolant is the key element of the heating system. The heater circuit is fed by a combination of coolant from the engine. Flow from these components provides heated coolant to the heater core. Coolant enters the heater core through the inlet heater hose, in a pressurized state. Heater core and complete engine-cooling circuit flow is managed by a single electric water pump. The speed of the electric water pump is governed by many inputs including; coolant temperature, ambient temperature, and HVAC control settings. Coolant flow to the engine's radiator is managed by an electronically controlled valve. This electronic valve eliminates the need for the traditional thermostat valve.

The heater core is located inside the Heating, Ventilation, and Air Conditioning (HVAC) module. The heat of the coolant flowing through the heater core warms the ambient air drawn through the HVAC module. Heated air is distributed to the passenger compartment, through the HVAC module, for passenger comfort.

The amount of heat delivered to the passenger compartment is controlled by opening or closing the HVAC module air temperature door. The coolant exits the heater core through the return heater hose and is recirculated back through the engine cooling system.