Transfer Case Encoder Motor
The transfer case encoder motor (1) consists of a permanent magnet DC motor and gear reduction assembly. It is located on the left hand side of the transfer case. When activated, it turns the shift detent lever shaft of the transfer case clockwise or counterclockwise, to shift the transfer case by moving the shift forks and collar assemblies inside the transfer case. The encoder motor is controlled through a 12-volt circuit provided by the transfer case shift control module. This circuit consists of a driver on both the Motor Control A and Motor Control B circuits. The encoder motor is bi-directional to allow the motor to shift the transfer case from 4HI or 4HI Lock to NEUTRAL and 4LO Lock positions.
Both the motor control drivers and motor control return drivers can be turned on using a scan tool. You may also monitor Motor Control A and B circuits using a scan tool.