The heater core works inside the heater and evaporator unit, passing engine coolant from your engine while you drive. The heater core works by using fins to spread heat from the coolant to air flowing alongside it. It has two specific tube connections, and the correct placement of the heater hoses is essential before any work can be done. To safely replace the heater core in these two models, start by disconnecting the negative battery cable, using caution to drain the coolant fully. Ventilate well to prevent burns from steam, and collect all used coolant in a sealed container to keep pets safe. First, pull out the heater core hoses, then unclip the right corner cover and remove the glove box frame. After that, remove the programmer screen if your car has it and detach both the electric and vacuum wiring. After keeping connections to the installer, you can take off the heater core cover. Pull out the heater core's mounting screws and remove the core completely. Start by attaching the new heater core with retaining screws, putting the heater cover back, then linking and connecting the vacuum and electrical connectors and air mix valve link for the programmer. Once done, put on the heater core hoses. Before being done, attach the negative battery cable, put coolant in the system, and make sure the air mix valve works correctly by turning the temperature to 90°, waiting for the programmer arm to reach the highest heat, confirming the valve moves easily, starting with maximum heat before using a torque wrench to tighten the valve to closed. Reassemble everything by putting back the right side sound insulator and glove box module in place.