To prevent white smoke emissions at start up, the engine is equipped with an electric heater located between the intake manifold cover and the intake pipe. Under the proper conditions of coolant temperature, intake air temperature, barometric pressure, and ignition position, the engine control module turns on the heater system

The system is capable of delivering heat for 3 minutes after the engine is started.

If the intake heater system is malfunctioning for any reason, the engine will start and run without operating the intake heater system. The only concern may be the amount of white smoke present.

The basic components of the intake heater system are the intake air heater element, the intake air heater relay, the engine coolant temperature (ECT) sensor, the barometric pressure (BARO) sensor, the intake air temperature (IAT) sensor, and the engine control module (ECM).

There are two intake heater relays. One relay is located in the cab, and the other relay is located on the front of the intake manifold cover. They turn the 12 volt heater ON and OFF in response to a signal from the ECM. The heater element has a ground cable that must be connected to the engine.