Operation - Part Time Indicator; Operation - Full Time Indicator; Transmission - Jeep Wrangler 2001 Service Manual

8Js - 30 INSTRUMENT CLUSTER
SHIFT INDICATOR (TRANSFER CASE) (Continued)
cil-like cutout of the words "FULL TIME" in the
opaque layer of the instrument cluster overlay. The
dark outer layer of the overlay prevents the indicator
from being clearly visible when it is not illuminated.
A green lens behind the cutout in the opaque layer of
the cluster overlay causes the "FULL TIME" text to
appear in green through the translucent outer layer
of the overlay when it is illuminated from behind by
a Light Emitting Diode (LED) soldered onto the
instrument cluster electronic circuit board. When the
exterior lighting is turned On, the illumination inten-
sity of the full time indicator is one-step dimmable,
which is adjusted using the panel lamps dimmer con-
trol ring on the left multi-function switch control
stalk. The full time indicator is serviced as a unit
with the instrument cluster.

OPERATION - PART TIME INDICATOR

The part time indicator gives an indication to the
vehicle operator that a part time operating mode of
the four-wheel drive transfer case is selected. On
vehicles equipped with the standard Command-Trac
four-wheel drive system, the part time indicator
lights when the transfer case is engaged in the 4H or
4L positions. On vehicles in some markets where the
Selec-Trac four-wheel drive system is an available
option, the part time indicator lights when the trans-
fer case is engaged in the 4 X 4 Part Time or 4 Lo
positions. This indicator is controlled by a transistor
on the instrument cluster electronic circuit board,
and is controlled by a hard wired transfer case
switch input to the cluster. The part time indicator
Light Emitting Diode (LED) receives battery current
on the instrument cluster electronic circuit board
through the fused ignition switch output (run-start)
circuit whenever the ignition switch is in the On or
Start positions; therefore, the LED will always be off
when the ignition switch is in any position except On
or Start. The LED only illuminates when it is pro-
vided a path to ground by the instrument cluster
transistor. The instrument cluster will turn on the
part time indicator for the following reasons:
• Transfer Case Switch Input - Each time the
cluster detects a ground on the 4WD switch sense
(part time) circuit (transfer case switch closed = part
time 4WD selected) the part time indicator will be
illuminated. The indicator remains illuminated until
the 4WD switch sense (part time) input to the cluster
is an open circuit (transfer case switch open = part
time 4WD not selected), or until the ignition switch
is turned to the Off position, whichever occurs first.
• Actuator Test - Each time the cluster is put
through the actuator test, the part time indicator will
be turned on, then off again during the bulb check
portion of the test to confirm the functionality of the
LED and the cluster control circuitry.
2001 JEEP WRANGLER
The transfer case switch is connected in series
between ground and the 4WD switch sense (part-
time) input to the instrument cluster. The transfer
case switch input to the instrument cluster circuitry
can be diagnosed using conventional diagnostic tools
and methods. (Refer to 21 - TRANSMISSION/
TRANSAXLE/TRANSFER CASE - DESCRIPTION)
for more information on the transfer case switch. For
further diagnosis of the part time indicator or the
instrument cluster circuitry that controls the LED,
(Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING).

OPERATION - FULL TIME INDICATOR

The full time indicator gives an indication to the
vehicle operator that a full time operating mode of
the four-wheel drive transfer case is selected. On
vehicles in some markets where the Selec-Trac four-
wheel drive system is an available option, the full
time indicator lights when the transfer case is
engaged in the 4 X 4 Full Time position. This indica-
tor is controlled by a transistor on the instrument
cluster electronic circuit board, and is controlled by a
hard wired transfer case switch input to the cluster.
The full time indicator Light Emitting Diode (LED)
receives battery current on the instrument cluster
electronic circuit board through the fused ignition
switch output (run-start) circuit whenever the igni-
tion switch is in the On or Start positions; therefore,
the LED will always be off when the ignition switch
is in any position except On or Start. The LED only
illuminates when it is provided a path to ground by
the instrument cluster transistor. The instrument
cluster will turn on the full time indicator for the fol-
lowing reasons:
• Transfer Case Switch Input - Each time the
cluster detects a ground on the 4WD switch sense
(full time) circuit (transfer case switch closed = full
time 4WD selected) the full time indicator will be
illuminated. The indicator remains illuminated until
the 4WD switch sense (full time) input to the cluster
is an open circuit (transfer case switch open = full
time 4WD not selected), or until the ignition switch
is turned to the Off position, whichever occurs first.
• Actuator Test - Each time the cluster is put
through the actuator test, the full time indicator will
be turned on, then off again during the bulb check
portion of the test to confirm the functionality of the
LED and the cluster control circuitry.
The transfer case switch is connected in series
between ground and the 4WD switch sense (full-time)
input to the instrument cluster. The transfer case
switch input to the instrument cluster circuitry can
be diagnosed using conventional diagnostic tools and
methods. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/TRANSFER CASE - DESCRIPTION) for more
TJ