Oil Pressure Gauge Not Operating Properly

Using scan tool, check for PCM DTCs. If any OIL PRESSURE SENSOR VOLTS DTCs are set, go to SELF-DIAGNOSTICS - GRAND CHEROKEE article in ENGINE PERFORMANCE. If no OIL PRESSURE SENSOR VOLTS DTCs are present, turn ignition off. Press and hold TRIP/RESET button on instrument panel and turn ignition switch on. Mechanical Instrument Cluster (MIC) self-test will start. Oil pressure gauge should sweep from zero to full scale (high position), and back to zero. If oil pressure gauge reaches full scale and then returns to zero, go to appropriate SELF-DIAGNOSTICS - GRAND CHEROKEE article in ENGINE PERFORMANCE. If oil pressure gauge fails to reach full scale and return to zero, replace temperature/oil gauge pack. See appropriate INSTRUMENT PANELS article. Perform BODY VERIFICATION TEST  under VERIFICATION TESTS.