Exhaust Gas Recirculation: Description and Operation

PURPOSE
The exhaust gas recirculation (EGR) system recirculates exhaust gasses into the air/fuel mixture to lower combustion temperature. Oxides of Nitrogen (NOx) emissions are reduced as a result of lower combustion chamber temperatures. Operation is controlled by the ECM and exhaust system back-pressure.

CONSTRUCTION



The system consists of an EGR valve, vacuum modulator and a vacuum switching valve (VSV).

OPERATION

Schematic View Of EGR System Operation:

Diagnostic Chart Of EGR System Operational Conditions:

Refer to chart for operating conditions.