System Description

Fig 1: Sensor Description Chart

Courtesy of NISSAN MOTOR CO., U.S.A.

This system cuts and controls vacuum applied to the EGR valve to suit engine operating conditions. This cut-and-control operation is accomplished through the ECM and the EGRC solenoid valve. When the ECM detects any of the following conditions, current flows through the solenoid valve is cut. This causes the vacuum to be discharged into the atmosphere. The EGR valve remains closed.

• Low engine coolant temperature
• Engine stopped
• Engine starting
• High-speed engine operation
• Engine idling
• Excessively high engine coolant temperature
• High engine speed
• Wide open throttle
• Mass air flow sensor malfunction
• Low intake air temperature

Fig 2: EGR And Vacuum Chart

Courtesy of NISSAN MOTOR CO., U.S.A.