Instrument Cluster

Instrument Cluster
The instrument cluster used in the Jeep TJ contains six gauges and eleven warning lamps. The gauges are positioned with information received by the cluster over the CCD bus from the PCM. Some of the 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 display (VF) to count up from zero through nine. 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.


For 1997 Only; The VF display is also capable of displaying PCM DTCs in a numeric fashion rather than blinking the malfunction indicator lamp (MIL). This feature is accessed the same as in previous years by turning the key from off to run 3 times and staying in the run position.

The 1997 TJ cluster provides bus bias and the engine controller provides termination. If either of these components are disconnected, the bus will not be operational. Starting in 1998, the cluster also provides termination as a backup to the engine controller.


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 rear cover assembly. No internal parts of the cluster will be serviced Engine Temp Critical - when gauge reaches the high end of the red zone
Oil Pressure Low - below 6 psi and above 300 RPM
Volt Gauge Low - when engine controller sets the "charge fail" DTC.
Volt Gauge High - when engine controller sets the "voltage high" DTC..


Normal Operation: At key on, the cluster will light the low fuel, seat belt, check gauges, airbag and/or smart key immobilizer and upshift lamps (if equipped). As the key is turned farther towards the start position, the ABS (if equipped) and 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 PCM, 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 will display dashes. VF dimming is handled by the potentiometer that controls instrumentation illumination. Added for 1998 the odometer will remain in the last mode selected, trip or vehicle mileage after each key cycle.