Jeep Wrangler TJ 2003, Service Manual

Page: 9 / 66

ward press of the axle lock switch will operate the
front locker relay and front locker pump. The first
downward press on the axle lock switch locks the
rear axle, the second downward press locks the
front axle (rear is still locked), the third downward
press unlocks the front axle (rear is still locked), the
fourth downward press locks the front axle (rear
axle is still locked). An upward press on the axle
lock switch at any time will unlock any axle that is
currently locked.
The enabled axle lock switch energizes the locker
relay and voltage is sent to the locker pump to
supply 5 psi of air to the axle allowing the differen-
tial to lock up. The “axle lock” indicator on the
instrument cluster flashes during the transition
state. The instrument cluster is seeking lock feed-
back from the locking indicator switch. With a
successful lock request the “axle lock” indicator will
be illuminated and a chime will sound.
If an axle is engaged the axle lock switch remains
enabled until all axles are unlocked, regardless if
the key is removed from the ignition switch. If the
ignition key is removed and either axle is locked the
instrument cluster “axle lock” indicator to the cor-
responding axle will flash and the chime will sound
three times to alert of battery discharge. Flashing
“axle lock” indicators will continue until axles are
unlocked. Once the axles have been locked it will
remain locked until one of the following happens:
1. an upward press of the axle lock switch for all
locked axles or downward press for front axle
only
2. transfer case is shifted out of 4 “LOW” range
3. vehicle speed exceeds 72 km/h (45 mph)
4. loss of battery power
3.4 USING THE DRBIII
T
Refer to the DRBIII
t
user’s guide for instructions
and assistance with reading diagnostic trouble
codes, erasing trouble codes and other DRB func-
tions.
3.5 DRBIII
T
ERROR MESSAGES
Under normal operation, the DRBIII
t
will dis-
play one of only two error messages:
– User–Requested WARM Boot or User–Re-
quested COLD Boot
This is a sample of such an error message display:
ver: 2.14
date: 26 Jul93
file: key_itf.cc
date: Jul 26 1993
line: 548
err: 0x1
User-Requested COLD Boot
Press MORE to switch between this display
and the application screen.
Press F4 when done noting information.
3.5.1 DRBIII
T
DOES NOT POWER UP
(BLANK SCREEN)
If the LED’s do not light or no sound is emitted at
start up, check for loose cable connections or a bad
cable. Check the vehicle battery voltage (data link
16-way connector cavity 16). A minimum of 11 volts
is required to adequately power the DRBIII
t
. Also,
check for a good ground at the DLC.
If all connections are proper between the
DRBIII
t
and the vehicle or other devices, and the
vehicle battery is fully charged, and inoperative
DRBIII
t
may be the result of faulty cable or vehicle
wiring.
3.5.2 DISPLAY IS NOT VISIBLE
Low temperatures will affect the visibility of the
display. Adjust the contrast to compensate for this
condition.
4.0 DISCLAIMERS, SAFETY
WARNINGS
4.1 DISCLAIMERS
All information, illustrations, and specifications
contained in this manual are based on the latest
5
GENERAL INFORMATION