TM 1-1520-238-T-4 Change 1 6–117 6–50. HOD XMN 1 READING – DISPLAYS LOW OIL PRESSURE 6–50 Tools: Nomenclature Part Number Tool Kit, Aircraft SC518099CLA01 Mechanic’s Tool Kit, Electrical SC518099CLA06 Repairer’s Personnel Required: 67R Attack Helicopter Repairer 68X Armament/Electrical Systems Repairer 152FG Maintenance Test Pilot References: TM 1-1520-238-23 TM 1-1520-238-CL Equipment Conditions: Ref Condition TM 1-1520-238-CL Engine 1 operating 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. 1. Check HOD display for XMN 1 oil temperature reading. Is reading 140 C or higher? YES Go to paragraph 6–49 to troubleshoot HOD XMN 1 display. NO Go to step 2. 2. Check pilot caution/warning panel OIL PSI MAIN XMSN 1 indicator. Is indicator lighted? YES Go to paragraph 6–52 to troubleshoot OIL PSI MAIN XMSN 1 indicator. NO Go to step 3. 3. Check pilot caution/warning panel OIL HOT MAIN XMSN 1 indicator. Is indicator lighted? YES Go to step 4. NO Go to paragraph 6–51 to troubleshoot OIL HOT MAIN XMSN 1 indicator. 4. Check HOD display for XMN 1 oil pressure reading. Is reading oil pressure 35 LB or lower? YES Replace main transmission 1 primary pump (TM 1-1520-238-23). NO Main transmission 1 oil pressure is not critically low. Go to paragraph 6–13. END OF TASK