Jeep Cherokee (XJ): Description and operation

Trip computer

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:

  •  Compass and temperature
  •  Trip odometer (ODO)
  •  Average fuel economy (AVG ECO)
  •  Instant fuel economy (ECO)
  •  Distance to empty (DTE)
  •  Elapsed time (ET)
  •  Blank display.

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.

Compass

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.

Thermometer

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.

Reading and courtesy lamp

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.

Garage door opener storage bin

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.

Sunglasses storage bin

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.

    Previous pageGeneral information

    Introduction An overhead console featuring a mini trip computer, an electronic compass, and an outside ambient temperature thermometer is an available factory-installed option on this model. Refer ...

    Next pageDiagnosis and testing

    Trip computer, compass, and thermometer display module If the problem with the trip computer, compass, and thermometer display module is an inaccurate or scrambled display, use the Self-Diagnostic ...

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    Service warnings and precautions
    WARNING:  THE AIR CONDITIONING SYSTEM CONTAINS REFRIGERANT UNDER HIGH PRESSURE. SEVERE PERSONAL INJURY MAY RESULT FROM IMPROPER SERVICE PROCEDURES. REPAIRS SHOULD ONLY BE PERFORMED BY QUALIFIED SERVICE PERSONNEL.  AVOID BREATHING THE REFRIGERANT AND REFRIGERANT OIL VAPOR OR ...