Transfer Motor

WARNING: This page is about a different car, the 2003 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

The transfer motor drives the sub-oil pump to provide proper lubrication and oil pressure control when the vehicle is at standstill, during low-speed operations or is being driven in reverse.
The main oil pump is operated by the driving force of the mainshaft. In other words, sufficient oil pressure buildup does not occur when the vehicle is at standstill or during low-speed operations. While the vehicle is being driven in reverse, the main oil pump rotates in the reverse direction. Therefore the main oil pump does not discharge oil pressure. During any of the above vehicle operations, the transfer motor drives the sub-oil pump to compensate for insufficient oil pressure.
The transfer motor operates as follows:
1. The motor relay turns OFF in the 2WD mode.
2. The motor relay operates as described in the table below in modes other than the 2WD mode.
  Table 1
  
  Fig 1: Transfer Motor Operation Chart - 1
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Table 2
  
  Fig 2: Transfer Motor Operation Chart - 2
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  NOTE: OFF (after 2.5 seconds have elapsed.)
4WD shift switch, PNP switch, Neutral-4LO switch, vehicle speed sensor and throttle position sensor are used in conjunction with the transfer motor.