4.0L Engine

Fig 1: EGR System Diagram (4.0L Engine)

Courtesy of MAZDA MOTORS CORP.

The 4.0L engine, the powertrain control module (PCM) controls the EGR vacuum regulator solenoid. The EGR vacuum regulator solenoid controls the vacuum to the EGR valve. When the EGR valve opens, exhaust gas flows to the intake manifold to be returned to the combustion cycle. The differential pressure feedback EGR system monitors the flow and returns a signal to the powertrain control module (PCM).