System Description

Fig 1: Sensor Description

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 dose not flow through the solenoid valve. This causes the intake manifold vacuum to be discharged into the atmosphere. The EGR valve remains closed.

• Low engine coolant temperature
• Engine starting
• High-speed engine operation
• Engine idling
• Excessively high engine coolant temperature
• Mass air flow sensor malfunction

Fig 2: Identifying EGR And Vacuum

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