TM 1-1520-238-T-4 6–124 Change 1 6–55. OIL PSI MAIN XMSN 2 INDICATOR – IS LIGHTED WHEN HOD DISPLAYS NORMAL 6–55 XMN 2 OIL PRESSURE Tools: Nomenclature Part Number Tool Kit, Aircraft SC518099CLA01 Mechanic’s Tool Kit, Electrical SC518099CLA06 Repairer’s Tool Kit, Powertrain SC518099CLA013 Repairer’s Adapter, Straight Pipe A1100-4-4 to Tube, Female Pipe End, 37 Flared Gage Pressure, Dial GGG76 Indicating (0-200 PSI) Multimeter, Digital AN/PSM-45 Personnel Required: 67R Attack Helicopter Repairer 68D Aircraft Powertrain Repairer/NDI 68X Armament/Electrical Systems Repairer 152FG Maintenance Test Pilot References: TM 1-1520-238-T-6 TM 1-1520-238-23 TM 1-1520-238-CL TM 9-1230-476-20-2 Equipment Conditions: Ref Condition TM 1-1520-238-23 Access provisions – L60 fairing and L200, L325, T250L, T250R, T290L, T290R and T325 access doors open WARNING Turn off power before detaching or attaching wires and connectors. High current 28 VDC or 115 VAC is present. Failure to do so could result in death or serious injury. NOTE Verify transmission system operating temperature is normal during flight. Low oil pressure may may have resulted from high NGB 1 oil temperature. 1. Detach P18. Is OIL PSI MAIN XMSN 2 indicator lighted(see note)? YES Refer to TM 1-1520-238-T-6 to troubleshoot the pilot caution/warning system. NO Go to step 2. 2. Detach P755. Check for short between P18–10 and ground. Does short exist? YES Repair shorted wire between P18–10 and P755–15. Go to paragraph 6–13. NO Go to step 3. 3. Check for open between: P18–10 and P456–A1, J456–A1 and P755–15, P755–16 and ground. Does open exist? YES Repair open wire. Go to paragraph 6–13. NO Go to step 4. 4. Attach P18 and P755. Check for open between J456–A1 and ground. Does open exist? YES Replace main transmission oil system 2 oil pressure switch (TM 1-1520-238-23). NO Go to step 5.