EGR Control Module: Description and Operation

Purpose:
The exhaust gas recirculation (Linear EGR) system is used to decrease the emission levels of oxides of nitrogen (NOx). NOx is a group of chemical compounds containing nitrogen and varying amounts of oxygen that can have harmful environmental effects in large quantities.

Operation:
The linear EGR system consists of the PCM, the linear EGR valve, and EGR valve signal modifier module assembly. The EGR module is required because the PCM driver does not have the current capability to drive the EGR valve on its own.

Based on the inputs to the PCM a pintle position (pulse width) is commanded to the EGR module. The EGR module then reads this signal and commands a pintle position to the linear EGR valve directly. The EGR module connection consists of ignition voltage, a ground circuit, an input signal from the PCM and the EGR valve control circuit.