Operating Instructions - Overview QSC8.3 and QSL9 Page 1-2 Section 1 - Operating Instructions Check the oil pressure indicators, temperature indicators, warning lights, and other gauges daily to make sure they are operational. Check the oil pressure, coolant temperatures DEF level, and other engine parameters daily via the OEM front panel to make sure they are operational. Check the panel regularly for any alarm messages. Take appropriate action to rectify the alarm condition or contact your nearest Authorized Cummins® Distributor.