The heater core heats the air before it enters the vehicle. Engine coolant is circulated through the core to heat the outside air passing over the fins of the core. The core is functional at all times (no water shut-off valve is used) and may be used to temper conditioned air in the A/C mode, as well as the heat or vent mode.
Disconnect the negative battery cable.
Remove the cosmetic/acoustic engine cover, as equipped.
Remove the air cleaner and duct assembly.
Drain the engine coolant into a suitable container.
On the 3.4L (VIN X) engine, remove the throttle body and the throttle body tube to which it mounts.
On some 3.1L engine, a Quick-Connect fitting as used, which requires a special tool to separate the fitting
Disconnect both heater hoses from the heater core. On some vehicles, accessing the firewall side heater hoses can be a challenge due to limited working space. In addition, some vehicles equipped with the 3.1L engine may have quick-connect fittings on the hose, requiring special tool J 38723 Heater Line Quick Connect Separator, or equivalent.
Remove the lower center console, if equipped. Additional information may be found in the Control Panel service instructions, found in this section.
Remove both left and right underdash sound insulator panels.
Disconnect the lower heater duct.
Remove the heater core cover. The sealer usually should be discarded and replaced with new sealer. Evaluate the condition of the existing sealer and the availability of new sealer.
Locate and remove the heater core mounting clip and bracket and remove the heater core from the vehicle. Use care as it will likely have coolant inside and could drip onto the rugs or seats.
Installation is the reverse of the removal process. After refilling the cooling system, bleed out the air and check for leaks as outlined in of this guide.
Connect the negative battery cable.