WARNING: This page is about a different car, the 2004 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: System - Basic Engine Control System (1 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: System - Basic Engine Control System (2 Of 2)
Courtesy of NISSAN MOTOR CO., U.S.A.
1-6: The numbers refer to the order of inspection.