Exhaust Gas Recirculation (EGR) System Operation

WARNING: This page is about a different variant/trim than selected.

Intake air is mixed with cooled exhaust gas coming from the exhaust gas recirculation EGR valve. The exhaust gas mixes with the intake air to satisfy emissions, performance, fuel economy and cool the combustion process. The Mass Air Flow (MAF) sensor signal is used by the ECM to detect the proper amount of EGR flow. The ECM will close the EGR valve, then open the EGR valve to 100%. The ECM will then calculate the MAF difference and determine if the proper EGR flow has been detected. The recirculate gas also prevents the formation of NOx related gases, refer to as NOx emissions, which are a common cause for failing emissions testing. When a failure occurs both the air intake system and exhaust system should be checked in order to isolate the root cause.