Dodge RAM 1500 1998 Owner's Manual page 2242

DR
MODE SENSOR (Continued)
OPERATION
During normal vehicle operation, the Transfer Case
Control Module (TCCM) monitors the mode sensor
outputs at least every 250 (+/-50) milliseconds when
the shift motor is stationary and 400 microseconds
when the shift motor is active. A mode sensor signal
between 3.8 Volts and 0.8 Volts is considered to be
undefined.
Refer to SECTOR ANGLES vs. TRANSFER CASE
POSITION for the relative angles of the transfer case
shift sector versus the interpreted transfer case gear
operating mode. Refer to MODE SENSOR CHAN-
NEL STATES for the sensor codes returned to the
TCCM for each transfer case mode sensor position.
Transfer Case
Angle (degrees)
Between Gears
+40 (4LO)
Between Gears
Between Gears
+20 (NEUTRAL)
Between Gears
Between Gears
0 (2WD/AWD)
Between Gears
Between Gears
-20 (4HI)
Between Gears
Between Gears
SELECTOR SWITCH
DESCRIPTION
The selector switch assembly is mounted in the left
side of the vehicle's Instrument Panel (IP) and con-
sists of a rotary knob connected to a resistive net-
work for the mode and range shift selections. Also
located in this assembly is a recessed, normally open
momentary switch for making shifts into and out of
transfer case NEUTRAL. A pen, or similar instru-
ment, is used to make a NEUTRAL shift selection,
thus reducing the likelihood of an inadvertent shift
request.
MODE SENSOR CHANNEL STATES
Sensor Channel A
H
H
H
H
H
H
H
H
H
L
L
L
L
TRANSFER CASE - NV244 GENII
The various between gears positions can also be
referred as the transfer case's coarse position. These
coarse positions come into play during shift attempts.
SECTOR ANGLES VS. TRANSFER CASE POSITION
Shaft Angle (Degrees)
Sensor Channel B Sensor Channel C
H
H
H
L
L
L
L
L
L
L
L
L
H
The selector switch also contains light emitting
diode's (LED's) to indicate the transfer case position
and whether a shift is in progress.
Transfer Case Position
+40
+20
0
-20
Sensor Channel D
L
L
L
L
L
L
H
H
H
H
H
H
H
21 - 539
4LO
N
2WD/AWD
4HI
H
L
H
H
L
H
H
L
H
H
L
H
H