Engine Emission Control

ENGINE EMISSION CONTROL

4.6L Exhaust Gas Recirculation (EGR) System Module

EGR System Components:

CAUTION: Do not remove any part of the engine emission control system. Operating the engine without the engine emission control system will reduce fuel economy and engine ventilation. This will weaken engine performance and shorten engine life.

The exhaust gas recirculation (EGR) system returns a portion of the exhaust gas to the intake manifold to reduce the combustion temperature. This results in lower nitrogen oxide formation.

The powertrain control module (PCM) controls the EGR valve opening with the vacuum regulator solenoid. When the EGR system module valve opens, exhaust gas flows to the intake manifold. The EGR system module transducer measures the change in pressure across the orifice located in the EGR system module gasket. This change in pressure signal is sent to the PCM providing an indication of the EGR mass flow that was delivered.

The EGR system module to exhaust manifold tube:
- connects the exhaust manifold to the EGR valve, and provides a path to deliver exhaust gas to the EGR valve.

The EGR system module transducer:
- measures the change in pressure across the orifice in the EGR system and sends a signal to the PCM indicting the EGR mass flow that was delivered.
- measures the manifold absolute pressure (MAP) and provides this signal to the PCM.

The EGR vacuum regulator solenoid uses input from the PCM to achieve the calibrated level of EGR flow for various engine operating conditions.

For further description and operation, refer to Computers and Control Systems.

All Gasoline Engines
All gasoline engines are equipped with a positive crankcase ventilation (PCV) system. The function of the PCV system is to circulate blow-by gases from the engine crankcase to the engine intake.

The PCV system consists of:
- PCV valve.
- PCV tube.

The PCV valve:
- controls the amount of ventilating air and blow-by gases going to the intake manifold.

For further description and operation, refer to Computers and Control Systems.