Cherokee 2WD L6-4.0L VIN S (1998)
Information Bus: Description and Operation
Instrument Cluster
Instrument Cluster
The instrument cluster for Jeep Cherokee (XJ) is available for two different versions: base with two gauges and premium with six gauges. The gauges are
positioned with information received by the cluster over the CCD bus from the PCM. Some of the warning lamps are hardwired and some are controlled
by the cluster using CCD bus information. The vehicle chime function is contained on the cluster circuit board, as well as the timer for the rear window
defogger. There is a self-test available for the cluster that will actuate all the gauges and place them at their calibration points. The test will not run if the
cluster sees engine RPM or vehicle speed. This test will light all CCD controlled lamps for verification of lamp operation. It also forces the odometer
Vacuum Fluorescent (VF) display to count up from all zero's through all nine's. The self-test routine can be entered by pushing and holding the trip reset
button while rotating the ignition key from the "off" to the "on" position, release the button after the test starts.
In the 97 MY, the VF display is also capable of displaying PCM. This feature is accessed the same as in previous years by turning the key from "off" to
"run" three times and staying in position.
The instrument cluster will provide bus bias and termination and the PCM controller provides a second termination. If cluster is disconnected, the bus
will not be biased.
The cluster will be serviced as an assembly. There will be limited parts available: bulbs and sockets, the front lens, the trip odometer stem cover and the
hood and rear cover assembly. No internal parts of the cluster will be serviced.
Normal Operation: At key "on," the cluster will light the low fuel, seat belt, check gauges, check engine, ABS and airbag lamps. As the key is turned
farther toward the "start" position, the brake warning lamp will illuminate. The Vacuum Fluorescent (VF) display will indicate the mileage stored inside
the cluster. If there is a bus failure and the cluster cannot receive distance pulses from the engine controller, the cluster will display the last mileage
stored until the ignition is turned off. If the cluster is receiving bus messages, but is unable to display odometer information because of an internal failure,
the odometer display dashes. VF dimming is handled by the potentiometer that controls instrumentation illumination.
