Cherokee 2WD L6-4.0L VIN S (1998)
Check Gauges Lamp: Description and Operation
SYSTEM OPERATION
The check gauges lamp gives an indication when certain gauges reflect a condition requiring immediate attention. The lamp is turned on by the
instrument cluster circuitry for about three seconds after the ignition switch is turned to the On position as a bulb test. After the bulb test, the lamp
is controlled by the instrument cluster circuitry based upon gauge data messages received from the Powertrain Control Module (PCM) on the
Chrysler Collision Detection (CCD) data bus.
The PCM uses several inputs to decide what gauge data messages are required. The PCM then sends the proper message to the instrument cluster
on the CCD data bus. The gauge data messages for which the instrument cluster is programmed to turn on the check gauges lamp are:
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Engine coolant temperature is high or critical
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Engine oil pressure is low
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Charging system failure
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System voltage is high.
