SENSOR-POSITION
DESCRIPTION
The transfer case position sensor (2) is an electronic
device whose output can be interpreted to indicate the
transfer case’s current operating mode. The sensor
consists of a five position, resistive multiplexed circuit
which returns a specific resistance value to the Pow-
ertrain Control Module (PCM) for each transfer case
operating mode. The sensor is located on the top of
the transfer case, just left of the transfer case center-
line and rides against the sector plate roostercomb.
The PCM supplies 5VDC (+/- 0.5V) to the sensor and
monitors the return voltage to determine the sector
plate, and therefore the transfer case, position.
OPERATION
During normal vehicle operation, the Powertrain Con-
trol Module (PCM) monitors the transfer case position
sensor return voltage to determine the operating mode
of the transfer case. Refer to the Operating Mode Ver-
sus Resistance table for the correct resistance for
each position. Note that the NEUTRAL position is
allowed to float between sensor positions 3 and 4. If a
resistance is measured anywhere in either range, the
sensor is operating correctly.
Operating Mode Versus Resistance
SENSOR POSITION
OPERATING MODE
SENSOR RESISTANCE (ohms)
1
2WD
1124-1243
2
4WD PART TIME
650-719
3
NEUTRAL
389-431
4
NEUTRAL
199-221
5
4WD LOW
57-64
Position Sensor Linear Movement
1 - POSITION 1 - 10mm ±0.5mm
2 - POSITION 2 - 12mm ±0.5mm
3 - POSITION 3 - 14mm ±0.5mm
4 - POSITION 4 - 16mm ±0.5mm
5 - POSITION 5 - 18mm ±0.5mm
6 - POSITION 6 - 20mm±0.5mm - FULL EXTENSION
21 - 856
TRANSFER CASE - NV231
KJ