ASSEMBLY-SHIFT MOTOR/MODE SENSOR
DESCRIPTION
The shift motor (1) is an electromechanical device
consisting of a DC permanent magnet motor, gear
train, and an analog position sensor. The shift motors’
overall function is to move and lock a gear that moves
the mode and range forks found in the transfer case.
This allows the transfer case to be shifted electrically
to multiple operating positions (4HI, 2WD, N (neutral),
and 4LO). The operating current of the shift motor
under stall conditions is 30 amps maximum at 72° F
with 13.5 volts, at the motor leads.
OPERATION
Shifting in the transfer case occurs when a Pulse Width Modulated (PWM) voltage is supplied to the shift motor by
the Front Control Module (FCM). A linear analog position sensor located inside the shift motor, provides the FCM
with the motors’ angular, rotational position. With this information, the FCM continuously knows the motors’ position,
and therefore allows it to accurately control the motors’ operation, including voltage polarity which is used to control
motor direction.
REMOVAL
NOTE: New shift motor assemblies are shipped in the 2WD/AWD position. If a new shift motor assembly
must be installed, it will be necessary to shift the transfer case to the 2WD/AWD position prior to motor
installation.
1. Raise the vehicle on a suitable hoist.
2. Disengage the wiring connector from the shift
motor and mode sensor assembly.
3. Remove the bolts (3) holding the shift motor and
mode sensor assembly (2) onto the transfer case
(1).
4. Separate the shift motor and mode sensor assem-
bly (2) from the transfer case (1).
21 - 912
TRANSFER CASE - NV233
ND