With the engine sufficiently cool, perform the following steps:

1. Remove the radiator cap.
2. Start the engine.
3. Let the engine idle.

Set the heater controls to the following:

1. The HTR mode, the full RED temperature.
2. The HIGH blower speed.

When the coolant flow in the radiator is visible through the filler neck, install the radiator cap.

Warm up the engine for about 20 minutes with the engine running. Drive the vehicle at 48 km/h (30 mph). Use an accurate thermometer in order to determine the temperature of the outside air and the temperature of the air discharged at the floor outlets. The minimum acceptable heater output temperatures at 4 different outside temperatures are represented in the table.

The heater system can produce excessive heat from a binding or obstructed temperature air valve. Another condition can be a hot air leak from the engine compartment to the blower inlet.