Intake Air Heater: Description and Operation

OPERATION

The air heater element is used to heat incoming air to the intake manifold. This is done to help engine starting and improve driveability with cool or cold outside temperatures.

Electrical supply for the air heater element is controlled by the Engine Control Module (ECM) through the air heater relay.

A heavy-duty cable connects the air heater element to the air heater relay. This cable will supply 12-volts to an individual heating element within the heater block assembly.

The following chart displays the pre-heat, or turn-on times (in seconds) of the wait-to-start lamp. If the intake manifold temperature is above 66.09 degrees Fahrenheit, the wait-to-start lamp will not illuminate. Consequently, the intake air heater element will not be activated.