Exhaust Gas Recirculation: Description and Operation

Exhaust Gas Recirculation (EGR) System (D17A2, D17A6 engines (2001-2003 models) and 2004-2005 models)

Refer to the System Diagram to see the functional layout of the system.

EGR Valve
The EGR valve lowers peak combustion temperatures and reduces oxides of nitrogen emissions (NOx) by recirculating exhaust gas through the intake manifold and into the combustion chambers.

Exhaust Gas Recirculation (EGR) System Diagram (D17A2, D17A6 engines (2001-2003 models) and all 2004-2005 models)




The EGR system reduces oxides of nitrogen (NOx) emissions by recirculating exhaust gas through the EGR valve and the intake manifold into the combustion chambers. The ECM/PCM memory includes the ideal EGR valve position for varying operating conditions.

The EGR valve position sensor detects the amount of EGR valve lift and sends it to the ECM/PCM. The ECM/PCM then compares it with the ideal lift in its memory (based on signals sent from other sensors). If there is any difference between the two, the ECM/PCM cuts current to the EGR valve.