The heating system consists of the following components:

Engine coolant is circulated through the heater core in order to heat the core. The heater core is then used to heat the air which is pushed through the fins of the core by the air delivery system. The amount of air allowed to pass through the heater core fins is determined by the position of the temperature valve, thus creating the desired temperature of the air delivered to the passenger compartment.

In any modes in which the air conditioning system is ON, the heater core in conjunction with the temperature valve position is used to heat the cool, dehumidified air coming through the evaporator core, to achieve the desired temperature of the delivered air.