Jeep Cherokee (XJ): Description and operation
A mini trip computer is available on this model to
provide several electronic functions and features. The
trip computer contains a central processing unit and
interfaces with other modules in the vehicle on the
Chrysler Collision Detection (CCD) data bus network.
The CCD data bus network allows the sharing of
sensor information. This helps to reduce wire harness
complexity, reduce internal controller hardware,
and reduce component sensor current loads. At the
same time, this system provides increased reliability,
enhanced diagnostics, and allows the addition of
many new feature capabilities. Some of the functions and features that the trip
computer supports and/or controls, include the following
display options: Momentarily depressing and releasing the Step
button when the ignition switch is in the On position
will cause the overhead console display to step
sequentially through the listed display options.
Momentarily depressing and releasing the U. S./Metric
button toggles the display between U. S. and Metric
measurements.
The push button (Step and U. S./Metric) switch
module in the overhead console is hard wired to the
trip computer. The compass flux-gate unit is integral
to the trip computer, compass, and thermometer display
module unit. Data input for all other trip computer
functions is received through CCD data bus
messages. The trip computer uses its internal programming
and all of these inputs to calculate and
display the requested data. If the data displayed is
incorrect, see Trip Computer, Compass, and Thermometer
Display Module - Self-Diagnostic Test in the
Diagnosis and Testing section of this group. If these
tests prove inconclusive, the use of a DRB scan tool
and the proper Diagnostic Procedures manual are
recommended for further testing of the trip computer
and the CCD data bus.
The trip computer, compass, and thermometer display
module cannot be repaired, and is only available
for service as a unit. If faulty or damaged, the complete
module must be replaced. The push button
(Step and U. S./Metric) switch module is serviced
separately. The compass will display the direction in which the
vehicle is pointed using the eight major compass
headings (Examples: north is N, northeast is NE). It
does not display the headings in actual degrees.
The self-calibrating compass unit requires no
adjusting in normal use. The only calibration that
may prove necessary is to drive the vehicle in three
complete circles, on level ground, in not less than 48
seconds. This will reorient the compass unit to its
vehicle.
The compass unit also will compensate for magnetism
the body of the vehicle may acquire during normal
use. However, avoid placing anything magnetic
directly on the roof of the vehicle. Magnetic mounts
for an antenna, a repair order hat, or a funeral procession
flag can exceed the compensating ability of
the compass unit if placed on the roof panel. Magnetic
bit drivers used on the fasteners that hold the
assembly to the roof header can also affect compass
operation. If the vehicle roof should become magnetized,
demagnetizing and calibration may be required
to restore proper compass operation. See Compass
Calibration or Compass Demagnetizing in the Service
Procedures section of this group for these procedures.
The compass, trip computer, and thermometer display
module cannot be repaired, and is only available
for service as a unit. If faulty or damaged, the complete
module must be replaced. The push button
(Step and U. S./Metric) switch module is serviced
separately. The thermometer displays the outside ambient
temperature. The temperature display can be
changed from Fahrenheit to Celsius using the U.
S./Metric button, located just rearward of the display
module. The displayed temperature is not an instant
reading of conditions, but an average temperature. It
may take the thermometer display several minutes
to respond to a major temperature change, such as
driving out of a heated garage into winter temperatures.
When the ignition switch is turned to the Off position,
the last displayed temperature reading stays in
the thermometer unit memory. When the ignition
switch is turned to the On position again, the thermometer
will display the memory temperature if the
engine coolant temperature is above about 52 C
(125 F). If the engine coolant temperature is below
about 52 C (125 F), the thermometer will display
the actual temperature sensed by the ambient temperature
sensor. The thermometer temperature display
update interval varies with the vehicle speed.
The thermometer function is supported by an
ambient temperature sensor. The sensor is mounted
outside the passenger compartment near the front
and center of the vehicle and is hard-wired to the
module. The ambient temperature sensor is available
as a separate service item.
The thermometer, compass, and trip computer display
module cannot be repaired, and are only available
for service as a unit. If faulty or damaged, the
complete module must be replaced. The push button
(Step and U. S./Metric) switch module and ambient
temperature sensor are serviced separately. All reading and courtesy lamps located in the overhead
console are activated by the door ajar switches.
When the doors are closed, the lamps can be individually
activated by depressing the corresponding lens When a door is open, depressing the lamp lens
switches will not turn the lamps off. Refer to Group
8L - Lamps, for diagnosis of the reading and courtesy
lamps.
The reading and courtesy lamp lens, and bulbs are
available for service replacement. The reading and
courtesy lamp holders and switches are only available
as part of the overhead console wire harness. If
any reading lamp switch is faulty or damaged, the
wire harness and all four switches must be replaced. A compartment in the overhead console is designed
to hold most garage door opener remote control
transmitters. The transmitter is mounted within the
compartment with an adhesive-backed hook and loop
fastener patch.
With the transmitter mounted in the storage bin,
adapter pegs located on the front of the storage bin
door are selected and mounted on a post near the
center of the storage bin door. The peg(s) selected
and/or the post must be long enough to depress the
button of the transmitter, when the garage door
opener storage bin door is depressed. The pegs may
be stacked, if necessary. Refer to the owner's manual
in the vehicle glove box for more information.
A transmitter mounting kit including the adhesivebacked
hook and loop fastener material and a selection
of pegs is available for service. The garage door
opener storage bin door assembly is also available for
service replacement. A sunglasses storage bin is included in the overhead
console. The interior of the bin is lined with a
foam rubber padding material to protect the sunglasses
from being scratched. This bin features a
push/push-type latching mechanism, and a viscous
dampening system for a fluid opening action.
The sunglasses storage bin door, latch, viscous
damper, hinge spring and housing are available for
service only as a complete module. If any part of this
unit is faulty or damaged, the entire module must be
replaced.Trip computer
Compass
Thermometer
Reading and courtesy lamp
Garage door opener storage bin
Sunglasses storage bin
Other materials:
Adjustments
STEERING GEAR
CAUTION: Steering gear must be adjusted in the
proper order. If adjustments are not performed in
order, gear damage and improper steering response
may result.
NOTE: Adjusting the steering gear in the vehicle is
not recommended. Remove gear from the vehicle
and drain the fluid. ...